Business Combinations [Abstract]
Schedule of Business Acquisitions, by Acquisition [Table]
Schedule of Business Acquisitions, by Acquisition [Table]
Business Acquisition
Business Acquisition [Axis]
Business Acquisition, Acquiree [Domain]
Business Acquisition, Acquiree [Domain]
Clinical Research Management Inc.
Clinical Research Management, Inc. [Member]
Clinical Research Management Inc. [Member]
Finite-Lived Intangible Assets by Major Class
Finite-Lived Intangible Assets by Major Class [Axis]
Finite-Lived Intangible Assets, Major Class Name [Domain]
Finite-Lived Intangible Assets, Major Class Name [Domain]
Customer lists
Customer Lists [Member]
Order backlog
Order or Production Backlog [Member]
Brand
Brand [Member]
Brand [Member]
Business Acquisition [Line Items]
Business Acquisition [Line Items]
Cash
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents
Property, plant and equipment
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment
Goodwill
Goodwill
Intangible assets
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles
Accounts receivable
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables
Unbilled revenue
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Unbilled Revenue
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Unbilled Revenue
Prepayments and other current assets
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets
Accounts payable
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable
Other liabilities
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other
Non-current other liabilities
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other
Net assets acquired
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net
Total consideration
Business Combination, Consideration Transferred
Restructuring and Related Activities [Abstract]
Schedule of Restructuring and Related Costs [Table]
Schedule of Restructuring and Related Costs [Table]
Restructuring Program [Axis]
Restructuring Program [Axis]
Restructuring Program [Axis]
Restructuring Program [Domain]
Restructuring Program [Domain]
Restructuring Program [Domain]
Workforce Reduction
Workforce Reduction [Member]
Workforce Reduction [Member]
Onerous Lease
Onerous Lease [Member]
Onerous Lease [Member]
Restructuring Plan
Restructuring Plan [Axis]
Restructuring Plan [Domain]
Restructuring Plan [Domain]
Resource Rationalizations
Resource Rationalizations [Member]
Resource Rationalizations [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve [Roll Forward]
Restructuring Reserve [Roll Forward]
Beginning provision
Restructuring Reserve
Total provision recognized
Restructuring Charges
Utilized
Restructuring Reserve Utilizations
Restructuring Reserve Utilizations
Foreign exchange
Restructuring Reserve, Foreign Currency Translation Gain (Loss)
Closing provision
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue [Table]
Disaggregation of Revenue [Table]
Customer [Axis]
Customer [Axis]
Customer [Domain]
Customer [Domain]
Top client
Top Client [Member]
Top Client [Member]
Clients 2-5
Clients 2-5 [Member]
Clients 2-5 [Member]
Clients 6-10
Clients 6-10 [Member]
Clients 6-10 [Member]
Clients 11-25
Clients 11-25 [Member]
Clients 11-25 [Member]
Other
Other Customers [Member]
Other Customers [Member]
Disaggregation of Revenue [Line Items]
Disaggregation of Revenue [Line Items]
Revenue
Revenue from Contract with Customer, Excluding Assessed Tax
Accounting Policies [Abstract]
New Accounting Pronouncements
New Accounting Pronouncements, Policy [Policy Text Block]
Basis of Presentation
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]
Earnings Per Share [Abstract]
Weighted average number of ordinary shares outstanding for basic net income per ordinary share (in shares)
Weighted Average Number of Shares Outstanding, Basic
Effect of dilutive share options outstanding (in shares)
Weighted Average Number Diluted Shares Outstanding Adjustment
Weighted average number of ordinary shares outstanding for diluted net income per ordinary share (in shares)
Weighted Average Number of Shares Outstanding, Diluted
Subsequent Events [Abstract]
Mapi Group [Member]
Mapi Group [Member]
Mapi group.
Other receivables
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Other Receivables
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Other Receivables
Income taxes receivable
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Income Taxes Receivable
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Income Taxes Receivable
Payments on account
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Payments on Account
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Payments on Account
Non-current deferred tax liability
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent
Cash outflows
Payments to Acquire Businesses, Gross
Working capital adjustment
Business Acquisition Purchase Price Allocation To Working Capital Increase (Decrease)
Business Acquisition Purchase Price Allocation To Working Capital Increase (Decrease)
Income Tax Disclosure [Abstract]
Provision for income taxes
Income Tax Expense Benefit Before Restructuring And Other Items
Income Tax Expense Benefit Before Restructuring And Other Items
Tax impact of restructuring and other items
Other Tax Expense (Benefit)
Tax impact of restructuring and other items
Income Tax Expense (Benefit)
Segment Reporting [Abstract]
Number of operating segments
Number of Operating Segments
Contracts Receivable [Abstract]
Trade accounts receivable, unbilled services and payments on account
Revenue from Contract with Customer [Text Block]
Segment Reporting Disclosure
Segment Reporting Disclosure [Text Block]
Statement of Cash Flows [Abstract]
Cash flows from operating activities:
Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract]
Net income
Net Income (Loss) Attributable to Parent
Adjustments to reconcile net income to net cash provided by operating activities:
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Loss on disposal of property, plant and equipment
Gain (Loss) on Disposition of Property Plant Equipment
Depreciation expense
Depreciation
Amortization of intangibles
Amortization of Intangible Assets
Amortization of government grants
Recovery of Amortization of Government Grants
Amortization of Government Grants.
Interest on short term investments
Accrued Interest On Short Term Bank Deposits
Accrued Interest On Short Term Bank Deposits
Stock compensation expense
Share-based Compensation
Amortization of gain on interest rate hedge
Amortization Of Gain On Interest Rate Hedge
Amortization Of Gain On Interest Rate Hedge
Amortization of financing costs
Amortization of Debt Issuance Costs
Deferred taxes
Deferred Income Taxes and Tax Credits
Changes in assets and liabilities:
Increase (Decrease) in Operating Capital [Abstract]
(Increase)/decrease in accounts receivable
Increase (Decrease) in Accounts Receivable
Increase in unbilled revenue
Increase (Decrease) in Contract with Customer, Asset
Increase (Decrease) in Contract with Customer, Asset
Increase in other receivables
Increase (Decrease) in Other Receivables
Decrease/(increase) in prepayments and other current assets
Increase (Decrease) in Prepaid Expense and Other Assets
Increase in other non-current assets
Increase (Decrease) in Other Noncurrent Assets
Increase/(decrease) in payments on account
Increase (Decrease) In Contract With Customer Liability
Increase (Decrease) In Contract With Customer Liability
Decrease in other current liabilities
Increase (Decrease) in Other Current Liabilities
Decrease in other non-current liabilities
Increase (Decrease) in Other Noncurrent Liabilities
(Decrease)/increase in income taxes payable
Increase (Decrease) in Income Taxes Payable
Decrease in accounts payable
Increase (Decrease) in Accounts Payable
Net cash provided by operating activities
Net Cash Provided by (Used in) Operating Activities
Cash flows from investing activities:
Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract]
Purchase of property, plant and equipment
Payments to Acquire Property, Plant, and Equipment
Purchase of subsidiary undertakings
Purchase of short term investments
Payments to Acquire Short-term Investments
Sale of short term investments
Proceeds from Sale of Short-term Investments
Net cash used in investing activities
Net Cash Provided by (Used in) Investing Activities
Cash flows from financing activities:
Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract]
Financing costs
Payments of Financing Costs
Proceeds from exercise of equity compensation
Proceeds from Stock Options Exercised
Share issue costs
Payments of Stock Issuance Costs
Repurchase of ordinary shares
Payments for Repurchase of Common Stock
Share repurchase costs
Payments for Share Repurchase Costs
Payments for Share Repurchase Costs
Net cash used in financing activities
Net Cash Provided by (Used in) Financing Activities
Effect of exchange rate movements on cash
Effect of Exchange Rate on Cash and Cash Equivalents
Net increase in cash and cash equivalents
Cash and Cash Equivalents, Period Increase (Decrease)
Cash and cash equivalents at beginning of period
Cash and Cash Equivalents, at Carrying Value
Cash and cash equivalents at end of period
Revenue, Initial Application Period Cumulative Effect Transition [Table]
Revenue, Initial Application Period Cumulative Effect Transition [Table]
Initial Application Period Cumulative Effect Transition [Axis]
Initial Application Period Cumulative Effect Transition [Axis]
Initial Application Period Cumulative Effect Transition [Domain]
Initial Application Period Cumulative Effect Transition [Domain]
Difference between Revenue Guidance in Effect before and after Topic 606
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Calculated under Revenue Guidance in Effect before Topic 606
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Adjustments for New Accounting Pronouncements [Axis]
Adjustments for New Accounting Pronouncements [Axis]
Type of Adoption [Domain]
Type of Adoption [Domain]
Accounting Standards Update 2014-09
Accounting Standards Update 2014-09 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cash flows from operating activities [Abstract]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Loss on disposal of property, plant and equipment
Depreciation expense
Amortization of government grants
Interest on short term investments
Stock compensation expense
Amortization of financing costs
Deferred taxes
Increase in accounts receivable
Increase (Decrease) in Contract with Customer, Asset
Increase in unbilled revenue
Increase (Decrease) in Unbilled Receivables
(Increase)/decrease in other receivables
Decrease in prepayments and other current assets
Increase in other non-current assets
Decrease in income taxes payable
Cash flows from investing activities [Abstract]
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchase of property, plant and equipment
Purchase of subsidiary undertakings
Purchase of short term investments
Sale of short term investments
Cash flows from financing activities [Abstract]
Net Cash Provided by (Used in) Financing Activities [Abstract]
Share issue costs
Repurchase of ordinary shares
Share repurchase costs
Equity Components [Axis]
Equity Components [Axis]
Equity Component [Domain]
Equity Component [Domain]
Common Stock [Member]
Common Stock [Member]
Additional Paid-in Capital
Additional Paid-in Capital [Member]
Other Undenominated Capital
Other Undenominated Capital [Member]
Other undenominated capital.
AOCI Attributable to Parent [Member]
AOCI Attributable to Parent [Member]
Retained Earnings [Member]
Retained Earnings [Member]
Ordinary shares, shares issued (in shares)
Common Stock, Shares, Issued
Beginning balance
Stockholders' Equity Attributable to Parent
Currency translation adjustment
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax
Currency impact of long term funding
Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment, Before Tax, Long Term Funding
Adjustment that results from the process of translating the impact of long-term funding into the functional currency of the reporting entity.
Tax on currency impact of long term funding
Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Long Term Funding Tax
Tax impact on the adjustment that results from the process of translating the impact of long-term funding into the functional currency of the reporting entity.
Unrealized capital gain – investments
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax
Amortization of interest rate hedge
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax
Fair value of cash flow hedge
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax
Total comprehensive income
Comprehensive Income (Loss), Net of Tax, Attributable to Parent
Exercise of share options (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period
Exercise of share options
Stock Issued During Period, Value, Stock Options Exercised
Issue of restricted share units (in shares)
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures
Issue of restricted share units
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures
Non-cash stock compensation expense
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition
Share issuance costs
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs
Share repurchase program (in shares)
Stock Repurchased and Retired During Period, Shares
Share repurchase program
Stock Repurchased and Retired During Period, Value
Share repurchase costs
Adjustment to Retained Earning Share Repurchase costs
Adjustment to Retained Earning Share Repurchase costs
Ending balance
Business Combinations
Business Combination Disclosure [Text Block]
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-based Awards
Disclosure of Compensation Related Costs, Share-based Payments [Text Block]
Statement of Stockholders' Equity [Abstract]
Statement [Table]
Statement [Table]
Ordinary Shares
Accumulated Other Comprehensive Income (Loss)
Retained Earnings
Statement [Line Items]
Statement [Line Items]
Balance (in shares)
Cumulative effect adjustment from adoption of ASC 606
Cumulative Effect of New Accounting Principle in Period of Adoption
Currency translation adjustment
Currency impact of long term funding (net of tax)
Unrealized capital gain – investments
Fair value of cash flow hedge (net of tax)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax
Exercise of share options
Issue of restricted share units
Non-cash stock compensation expense
Share issuance costs
Share repurchase program
Share repurchase costs
Balance (in shares)
Significant Accounting Policies
Significant Accounting Policies [Text Block]
Income Taxes
Income Tax Disclosure [Text Block]
Schedule of Segment Reporting Information, by Segment [Table]
Schedule of Segment Reporting Information, by Segment [Table]
Geographical
Geographical [Axis]
Geographical [Domain]
Geographical [Domain]
Ireland
IRELAND
Rest of Europe
Rest Of Europe [Member]
Rest Of Europe [Member]
U.S.
UNITED STATES
Rest of World
Rest of World [Member]
Rest of World [Member]
Segment Reporting Information [Line Items]
Segment Reporting Information [Line Items]
Revenue
Contracts Revenue
Schedule of summary of recognized identified assets acquired and liabilities assumed
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]
Assets
Assets
Schedule of components of income tax expense
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]
Schedule of share option activity
Share-based Compensation, Stock Options, Activity [Table Text Block]
Schedule of movement in non-vested share options
Schedule of Nonvested Share Activity [Table Text Block]
Schedule of weighted average fair values and assumptions used
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]
Schedule of RSU and PSU activity
Schedule Of Share Based Compensation Restricted Stock Units Performance Stock Units Award Activity [Table Text Block]
Schedule Of Share Based Compensation Restricted Stock Units Performance Stock Units Award Activity [Table Text Block]
Schedule of non-cash stock compensation expense
Schedule of Non Cash Stock Compensation Expense [Table Text Block]
Schedule of Non Cash Stock Compensation Expense.
Schedule of New Accounting Pronouncements and Changes in Accounting Principles
Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block]
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill [Roll Forward]
Goodwill [Roll Forward]
Opening balance
Current period acquisitions (Note 6)
Goodwill, Acquired During Period
Prior period acquisitions (Note 6)
Goodwill, Purchase Accounting Adjustments
Foreign exchange movement
Goodwill, Foreign Currency Translation Gain (Loss)
Closing balance
Equity [Abstract]
Share Capital
Stockholders' Equity Note Disclosure [Text Block]
Reconciliation of Number of Shares Used in Computation of Basic and Diluted Net Income Per Ordinary Share
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]
Net income per ordinary share
Earnings Per Share [Text Block]
Impact fo change in accounting policy
New Accounting Pronouncements and Changes in Accounting Principles [Text Block]
Statement of Financial Position [Abstract]
ASSETS
Assets [Abstract]
Current Assets:
Assets, Current [Abstract]
Cash and cash equivalents
Short term investments - available for sale
Available-for-sale Securities, Debt Securities, Current
Accounts receivable, net
Accounts Receivable, Net, Current
Unbilled revenue
Unbilled Contracts Receivable
Other receivables
Nontrade Receivables, Current
Prepayments and other current assets
Prepaid Expense and Other Assets, Current
Income taxes receivable
Income Taxes Receivable, Current
Total current assets
Assets, Current
Other Assets:
Assets, Noncurrent [Abstract]
Property, plant and equipment, net
Property, Plant and Equipment, Net
Other non-current assets
Other Assets, Noncurrent
Non-current income taxes receivable
Income Taxes Receivable, Noncurrent
Non-current deferred tax asset
Deferred Income Tax Assets, Net
Intangible assets
Finite-Lived Intangible Assets, Net
Total Assets
LIABILITIES AND SHAREHOLDERS’ EQUITY
Liabilities and Equity [Abstract]
Current Liabilities:
Liabilities, Current [Abstract]
Accounts payable
Accounts Payable, Current
Payments on account
Contract with Customer, Liability, Current
Other liabilities
Other Liabilities, Current
Income taxes payable
Accrued Income Taxes, Current
Total current liabilities
Liabilities, Current
Other Liabilities:
Liabilities, Noncurrent [Abstract]
Non-current bank credit lines and loan facilities
Long-term Line of Credit, Noncurrent
Non-current other liabilities
Other Liabilities, Noncurrent
Non-current government grants
Capital Government Grants Noncurrent
Noncurrent capital government grants, which are amortized and recognized in earnings over the grant period.
Non-current income taxes payable
Accrued Income Taxes, Noncurrent
Non-current deferred tax liability
Deferred Income Tax Liabilities, Net
Commitments and contingencies
Commitments and Contingencies
Total Liabilities
Liabilities
Shareholders' Equity:
Stockholders' Equity Attributable to Parent [Abstract]
Ordinary shares
Common Stock, Value, Issued
Additional paid‑in capital
Additional Paid in Capital, Common Stock
Other undenominated capital
Other Undenominated Capital
Other undenominated capital.
Accumulated other comprehensive income
Accumulated Other Comprehensive Income (Loss), Net of Tax
Retained earnings
Retained Earnings (Accumulated Deficit)
Total Shareholders' Equity
Total Liabilities and Shareholders' Equity
Liabilities and Equity
Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table]
Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table]
Award Type
Award Type [Axis]
Equity Award [Domain]
Equity Award [Domain]
Performance Share Unit (PSUs)
Performance Share Unit [Member]
Performance Share Unit [Member]
Restricted Stock Units (RSUs)
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding Number of Shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at beginning of period (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number
Granted (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period
Shares vested (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period
Forfeited (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period
Outstanding at ending of period (in share)
Weighted Average Fair Value
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Outstanding at beginning of period (USD per share)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value
Granted (USD per share)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value
Shares vested (USD per share)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value
Forfeited (USD per share)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value
Outstanding at end of period (USD per share)
Weighted Average Remaining Contractual Life
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Outstanding at end of period
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms
Compensation Related Costs Share Based Payments Disclosure [Table]
Compensation Related Costs Share Based Payments Disclosure [Table]
Compensation Related Costs Share Based Payments Disclosure [Table]
PSUs Based on Service and EPS Targets
Performance Based Grants [Member]
Performance Based Grants [Member]
Employee Stock Plan, 2008 Plan
Employee Stock Plan, 2008 Plan [Member]
Employee Stock Plan, 2008 Plan [Member]
Employee Stock Plan, 2003 Plan
Employee Stock Plan, 2003 Plan [Member]
Employee Stock Plan, 2003 Plan [Member]
Employee Stock Option
Employee Stock Option [Member]
Restricted Stock Units 2008
Restricted Stock Units Twenty Zero Eight [Member]
Restricted Stock Units Twenty Zero Eight [Member]
Restricted Stock Units 2013
Restricted Stock Units Twenty Thirteen [Member]
Restricted Stock Units Twenty Thirteen [Member]
Range
Range [Axis]
Range [Domain]
Range [Domain]
Minimum
Minimum [Member]
Maximum
Maximum [Member]
Plan Name
Plan Name [Axis]
Plan Name [Domain]
Plan Name [Domain]
Individual Employee
Employee [Member]
Employee [Member]
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Additional number of ordinary shares which have been reserved for issuance
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized
Ordinary shares which have been reserved for issuance
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized
Limit of shares issued or to be issued pursuant to options granted
Limit of Shares Issued or To Be Issued Pursuant to Options Granted
Limit of Shares Issued or To Be Issued Pursuant to Options Granted
Percentage of option price for fair value of ordinary share
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent
Maximum number of award as percentage of shares outstanding
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Outstanding Stock Maximum
Shares vesting period
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period
Shares expiration period
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period
Weighted average contractual term of options outstanding
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term
Options outstanding fair value
Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Option Price
Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Option Price
Weighted average fair value per option
Share Based Compensation Arrangement by Share Based Payment Award, Options, Grants in Period, Weighted Average Option Price
Share Based Compensation Arrangement by Share Based Payment Award, Options, Grants in Period, Weighted Average Option Price
Exercisable - number of shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number
Exercisable - weighted average remaining contractual life
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term
Exercisable - weighted average exercise price
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price
Fully vested total intrinsic value
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value
Intrinsic value of option exercised
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value
Fair value of stock units vested
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value
Stock units granted
Stock units to be granted
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant
Cumulative EPS vesting period
Share Based Compensation Arrangement by Share Based Payment Award Other Than Options Expected Vesting Period
Share Based Compensation Arrangement by Share Based Payment Award Other Than Options Expected Vesting Period
Non-cash stock compensation expense not yet recognized
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized
Unrecognized stock-based compensation expense, weighted average period (years)
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition
Revenues [Abstract]
Revenues [Abstract]
Revenue
Revenue from Contract with Customer, Excluding Assessed Tax, Gross
Revenue from Contract with Customer, Excluding Assessed Tax, Gross
Reimbursable expenses
Revenue from Contract with Customer, Excluding Assessed Tax, Reimbursable Expenses
Revenue from Contract with Customer, Excluding Assessed Tax, Reimbursable Expenses
Total Revenue
Costs and expenses [Abstract]
Operating Expenses [Abstract]
Direct costs
Direct Operating Costs
Direct Costs, Reimbursable Expenses
Direct Costs, Reimbursable Expenses
Direct Costs, Reimbursable Expenses
Direct Costs, Other
Direct Costs, Other
Direct Costs, Other
Selling, general and administrative expense
Selling, General and Administrative Expense
Depreciation and amortization
Depreciation, Depletion and Amortization, Nonproduction
Restructuring charges
Total costs and expenses
Costs and Expenses
Income from operations
Operating Income (Loss)
Interest income
Investment Income, Interest
Interest expense
Interest Expense, Debt
Provision for income taxes
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Table]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Table]
Tax Period [Axis]
Tax Period [Axis]
Tax Period [Domain]
Tax Period [Domain]
Earliest Tax Year
Earliest Tax Year [Member]
Latest Tax Year
Latest Tax Year [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Liability for unrecognized tax benefit
Unrecognized Tax Benefits
Items generating unrecognized tax benefits
Unrecognized Tax Benefits, Current Year Tax Positions
Unrecognized Tax Benefits, Current Year Tax Positions
Interest and related penalties
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued
Tax year subject to examination by major tax jurisdictions
Open Tax Year
Weighted average grant date fair value
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value
Assumptions:
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected volatility
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate
Dividend yield
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate
Risk-free interest rate
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate
Expected life
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term
Class of Treasury Stock [Table]
Class of Treasury Stock [Table]
Share Repurchase Program
Share Repurchase Program [Axis]
Share Repurchase Program [Domain]
Share Repurchase Program [Domain]
Buyback Program
Buyback Program [Member]
Buyback Program [Member]
Equity, Class of Treasury Stock [Line Items]
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount
Stock Repurchase Program, Authorized Amount
Share repurchase program, authorized percentage
Stock Repurchase Program Authorized Percentage
Stock Repurchase Program Authorized Percentage
Ordinary shares repurchased
Treasury Stock, Shares, Acquired
Ordinary shares repurchased, value
Treasury Stock, Value, Acquired, Cost Method
Schedule of Contracts with Customers, Asset and Liabilities
Contract with Customer, Asset and Liability [Table Text Block]
Goodwill
Goodwill Disclosure [Text Block]
Schedule of Goodwill
Schedule of Goodwill [Table Text Block]
Billed services (accounts receivable)
Billed Contracts Receivable
Trade accounts receivable and unbilled revenue
Contracts Receivable, Gross
Contracts Receivable
Allowance for doubtful accounts
Allowance for Doubtful Accounts Receivable
Trade accounts receivable and unbilled revenue, net
Contracts Receivable, Net
Contracts Receivable, Net
Unearned revenue (payments on account)
Contract with Customer, Liability
Change in unbilled receivables
Change in Unbilled Receivables
Change in Unbilled Receivables
Change in unbilled receivables, percent
Change in Unbilled Receivables, Percent
Change in Unbilled Receivables, Percent
Change in customer advances and deposits
Change in Customer Advances and Deposits
Change in Customer Advances and Deposits
Change in customer advances and deposits, percent
Change in Customer Advances and Deposits, Percent
Change in Customer Advances and Deposits, Percent
Net balance
Advance Payments Netted Against Unbilled Contracts Receivable
Advance Payments Netted Against Unbilled Contracts Receivable
Change in advance payments netted against unbilled contracts receivable
Change in Advance Payments Netted Against Unbilled Contracts Receivable
Change in Advance Payments Netted Against Unbilled Contracts Receivable
Change in advance payments netted against unbilled contracts receivable, percent
Change in Advance Payments Netted Against Unbilled Contracts Receivable, Percent
Change in Advance Payments Netted Against Unbilled Contracts Receivable, Percent
Distribution of Net Revenue by Geographical Area
Revenue from External Customers by Geographic Areas [Table Text Block]
Distribution of Income from Operations by Geographical Area
Operating Income by Geography [Table Text Block]
Operating Income by Geography.
Distribution of Property, Plant and Equipment, Net, by Geographical Area
Long-lived Assets by Geographic Areas [Table Text Block]
Distribution of Depreciation and Amortization by Geographical Area
Schedule Of Depreciation And Amortization Expense By Geographical Area [Table Text Block]
Schedule Of Depreciation And Amortization Expense By Geographical Area.
Distribution of Total Assets by Geographical Area
Reconciliation of Assets from Segment to Consolidated [Table Text Block]
Income Statement [Abstract]
Revenue:
Costs and expenses:
Cost of Revenue [Abstract]
Selling, general and administrative expense
Depreciation and amortization
Restructuring
Interest income
Interest expense
Provision for income taxes
Net income
Net income per Ordinary Share:
Basic (USD per share)
Earnings Per Share, Basic
Diluted (USD per share)
Earnings Per Share, Diluted
Weighted average number of Ordinary Shares outstanding:
Weighted Average Number of Shares Outstanding, Diluted [Abstract]
Basic (in shares)
Diluted (in shares)
Ordinary shares, par value (in EUR per share)
Common Stock, Par or Stated Value Per Share
Ordinary shares, shares authorized (in shares)
Common Stock, Shares Authorized
Ordinary shares, shares outstanding (in shares)
Common Stock, Shares, Outstanding
Options Outstanding Number of Shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares [Roll Forward]
Beginning Balance (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares
Granted (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross
Vested (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares
Forfeited (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested Options Forfeited, Number of Shares
Ending Balance (in shares)
Weighted Average Exercise Price
Share Based Compensation Arrangement By Share Based Payment Award Nonvested Options Outstanding Exercise Price Abstract
Share Based Compensation Arrangement By Share Based Payment Award Nonvested Options Outstanding Exercise Price Abstract
Beginning balance (USD per share)
Share Based Compensation Arrangement by Share Based Payment Award, Nonvested Options, Outstanding Weighted Average Exercise Price
Share Based Compensation Arrangement by Share Based Payment Award, Nonvested Options, Outstanding Weighted Average Exercise Price
Granted (USD per share)
Share Based Compensation Arrangement by Share Based Payment Award, Nonvested Options, Granted in Period Weighted Average Exercise Price
Share Based Compensation Arrangement by Share Based Payment Award, Nonvested Options, Granted in Period Weighted Average Exercise Price
Vested (USD per share)
Share Based Compensation Arrangement by Share Based Payment Award, Nonvested Options, Vested in Period Weighted Average Exercise Price
Share Based Compensation Arrangement by Share Based Payment Award, Nonvested Options, Vested in Period Weighted Average Exercise Price
Forfeited (USD per share)
Share Based Compensation Arrangement by Share Based Payment Award, Nonvested Options, Forfeited in Period Weighted Average Exercise Price
Share Based Compensation Arrangement by Share Based Payment Award, Nonvested Options, Forfeited in Period Weighted Average Exercise Price
Ending balance (USD per share)
Weighted Average Fair Value
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Beginning Balance (USD per share)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value
Granted (USD per share)
Vested (USD per share)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Weighted Average Grant Date Fair Value
Forfeited (USD per share)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested Options Forfeited, Weighted Average Grant Date Fair Value
Ending Balance (USD per share)
Income from operations
Income from operations excluding restructuring
Operating Income (Loss) Excluding Restructuring
Operating Income (Loss) Excluding Restructuring
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs, by Report Line
Income Statement Location [Axis]
Income Statement Location [Domain]
Income Statement Location [Domain]
Direct costs
Cost of Sales [Member]
Selling, general and administrative
Selling, General and Administrative Expenses [Member]
Prior period workforce reduction
Prior period workforce reduction [Member]
Prior period workforce reduction [Member]
Workforce Reduction
Onerous Lease
Utilization
Short term investments - available for sale
Accounts receivable, net
Unbilled revenue
Other receivables
Income taxes receivable
Other non-current assets
Intangible assets
Accounts payable
Other liabilities
Income taxes payable
Non-current bank credit lines and loan facilities
Non-current government grants
Shareholders' Equity:
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Common Stock, Value, Issued
Accumulated other comprehensive income
Retained earnings
Options Outstanding Number of Shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at beginning of period (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number
Granted (in shares)
Exercised (in shares)
Forfeited (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period
Outstanding at end of period (in shares)
Exercisable at end of period
Weighted Average Exercise Price
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Outstanding at beginning of period (USD per share)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price
Granted (USD per share)
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price
Exercised (USD per share)
Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price
Forfeited (USD per share)
Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price
Outstanding at end of period (USD per share)
Exercisable at end of period (USD per share)
Weighted Average Fair Value
Share-based Compensation Arrangement by Share-based Payment Award, Options, Weighted Average Grant Date Fair Value [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Weighted Average Grant Date Fair Value [Abstract]
Outstanding at beginning of period (USD per share)
Share Based Compensation Arrangement by Share Based Payment Award, Options, Weighted Average Grant Date Fair Value
Share Based Compensation Arrangement by Share Based Payment Award, Options, Weighted Average Grant Date Fair Value
Exercised (USD per share)
Share Based Compensation Arrangement By Share Based Payment Award Options Exercised In Period Weighted Average Grant Date Fair Value
Share Based Compensation Arrangement By Share Based Payment Award Options Exercised In Period Weighted Average Grant Date Fair Value
Forfeited (USD per share)
Share Based Compensation Arrangement by Share Based Payment Award, Forfeited in Period, Weighted Average Grant Date Fair Value
Share Based Compensation Arrangement by Share Based Payment Award, Forfeited in Period, Weighted Average Grant Date Fair Value
Outstanding at end of period (USD per share)
Exercisable at end of period (USD per share)
Share Based Compensation Arrangement by Share Based Payment Award, Options, Exercisable, Weighted Average Grant Date Fair Value
Share Based Compensation Arrangement by Share Based Payment Award, Options, Exercisable, Weighted Average Grant Date Fair Value
Weighted Average Remaining Contractual Life
Share-based Compensation Arrangement by Share-based Payment Award, Options, Weighted Average Remaining Contractual Term [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Weighted Average Remaining Contractual Term [Abstract]
Outstanding at end of period
Exercisable at end of period
Restructuring
Restructuring and Related Activities Disclosure [Text Block]
Revenue, remaining performance obligation
Revenue, Remaining Performance Obligation
Revenue, remaining performance obligation, percent
Revenue, Remaining Performance Obligation, Percent
Revenue, Remaining Performance Obligation, Percent
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period
Restructuring Charges
Restructuring and Related Costs [Table Text Block]
Details of Movement in Restructuring Provisions Recognized
Schedule of Restructuring Reserve by Type of Cost [Table Text Block]
Document And Entity Information [Abstract]
Document And Entity Information [Abstract]
Document Type
Document Type
Amendment Flag
Amendment Flag
Document Period End Date
Document Period End Date
Document Fiscal Year Focus
Document Fiscal Year Focus
Document Fiscal Period Focus
Document Fiscal Period Focus
Trading Symbol
Trading Symbol
Entity Registrant Name
Entity Registrant Name
Entity Central Index Key
Entity Central Index Key
Current Fiscal Year End Date
Current Fiscal Year End Date
Revenue
Asset Impairment
Asset Impairment [Member]
Asset Impairment [Member]
Restructuring Plan [Axis]
Manchester Facility
Manchester Facility [Member]
Manchester Facility [Member]
Asset write off
Asset Impairment Charges
Balance Sheet Location [Axis]
Balance Sheet Location [Axis]
Balance Sheet Location [Domain]
Balance Sheet Location [Domain]
Other Current Liabilities
Other Current Liabilities [Member]
Other Noncurrent Liabilities
Other Noncurrent Liabilities [Member]
Restructuring Plan [Axis]
Resource Rationalizations
Asset impairment charges
Restructuring reserve, current
Restructuring Reserve, Current
Restructuring reserve, noncurrent
Restructuring Reserve, Noncurrent
Restructuring Reserve
Business Acquisition [Axis]
Income Statement Location [Axis]
Selling, General and Administrative Expenses [Member]
Cash outflows on acquisition
Payments to Acquire Businesses, Net of Cash Acquired
Estimate of intangible assets acquired
Certain payments made on behalf of business acquired
Business Combination, Consideration Transferred, Liabilities Incurred
Contingent consideration
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High
Fair value of contingent consideration liability
Business Combination, Contingent Consideration, Liability
Contingent consideration recorded in SG&A costs
Business Combination, Acquisition Related Costs
Fair value adjustments made to unbilled revenue
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Unbilled Revenue
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Unbilled Revenue
Fair value adjustments made to other liabilities
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Current Liabilities, Other
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Current Liabilities, Other
Fair value adjustments made to AR acquired
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Receivables
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Receivables
Fair value of adjustments made to accounts payable
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Accounts Payable
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Accounts Payable
Schedule of Disaggregation of Revenue
Disaggregation of Revenue [Table Text Block]