0000001 - Document - Cover link:presentationLink link:calculationLink link:definitionLink 0000002 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS link:presentationLink link:calculationLink link:definitionLink 0000003 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) link:presentationLink link:calculationLink link:definitionLink 0000004 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) link:presentationLink link:calculationLink link:definitionLink 0000005 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) link:presentationLink link:calculationLink link:definitionLink 0000006 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (UNAUDITED) link:presentationLink link:calculationLink link:definitionLink 0000007 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) link:presentationLink link:calculationLink link:definitionLink 0000008 - Disclosure - Basis of presentation link:presentationLink link:calculationLink link:definitionLink 0000009 - Disclosure - Summary of significant accounting policies link:presentationLink link:calculationLink link:definitionLink 0000010 - Disclosure - Revenue link:presentationLink link:calculationLink link:definitionLink 0000011 - Disclosure - Accounts receivable, unbilled revenue (contract assets) and unearned revenue or payments on account (contract liabilities) link:presentationLink link:calculationLink link:definitionLink 0000012 - Disclosure - Goodwill link:presentationLink link:calculationLink link:definitionLink 0000013 - Disclosure - Intangible assets link:presentationLink link:calculationLink link:definitionLink 0000014 - Disclosure - Fair value measurements link:presentationLink link:calculationLink link:definitionLink 0000015 - Disclosure - Restructuring link:presentationLink link:calculationLink link:definitionLink 0000016 - Disclosure - Operating leases link:presentationLink link:calculationLink link:definitionLink 0000017 - Disclosure - Bank credit lines and loan facilities link:presentationLink link:calculationLink link:definitionLink 0000018 - Disclosure - Derivatives link:presentationLink link:calculationLink link:definitionLink 0000019 - Disclosure - Income taxes link:presentationLink link:calculationLink link:definitionLink 0000020 - Disclosure - Net income per ordinary share link:presentationLink link:calculationLink link:definitionLink 0000021 - Disclosure - Share-based awards link:presentationLink link:calculationLink link:definitionLink 0000022 - Disclosure - Share capital link:presentationLink link:calculationLink link:definitionLink 0000023 - Disclosure - Business Segment and Geographical Information link:presentationLink link:calculationLink link:definitionLink 0000024 - Disclosure - Subsequent events link:presentationLink link:calculationLink link:definitionLink 9954701 - Disclosure - Summary of significant accounting policies (Policies) link:presentationLink link:calculationLink link:definitionLink 9954702 - Disclosure - Summary of significant accounting policies (Tables) link:presentationLink link:calculationLink link:definitionLink 9954703 - Disclosure - Revenue (Tables) link:presentationLink link:calculationLink link:definitionLink 9954704 - Disclosure - Accounts receivable, unbilled revenue (contract assets) and unearned revenue or payments on account (contract liabilities) (Tables) link:presentationLink link:calculationLink link:definitionLink 9954705 - Disclosure - Goodwill (Tables) link:presentationLink link:calculationLink link:definitionLink 9954706 - Disclosure - Intangible assets (Tables) link:presentationLink link:calculationLink link:definitionLink 9954707 - Disclosure - Fair Value Measures and Disclosures (Tables) link:presentationLink link:calculationLink link:definitionLink 9954708 - Disclosure - Restructuring (Tables) link:presentationLink link:calculationLink link:definitionLink 9954709 - Disclosure - Operating leases (Tables) link:presentationLink link:calculationLink link:definitionLink 9954710 - Disclosure - Bank credit lines and loan facilities (Tables) link:presentationLink link:calculationLink link:definitionLink 9954711 - Disclosure - Derivatives (Tables) link:presentationLink link:calculationLink link:definitionLink 9954712 - Disclosure - Income taxes (Tables) link:presentationLink link:calculationLink link:definitionLink 9954713 - Disclosure - Net income per ordinary share (Tables) link:presentationLink link:calculationLink link:definitionLink 9954714 - Disclosure - Share-based awards (Tables) link:presentationLink link:calculationLink link:definitionLink 9954715 - Disclosure - Business Segment and Geographical Information (Tables) link:presentationLink link:calculationLink link:definitionLink 9954716 - Disclosure - Summary of significant accounting policies - Estimated Useful Lives of Intangible Assets (Details) link:presentationLink link:calculationLink link:definitionLink 9954717 - Disclosure - Revenue (Details) link:presentationLink link:calculationLink link:definitionLink 9954718 - Disclosure - Accounts receivable, unbilled revenue (contract assets) and unearned revenue or payments on account (contract liabilities) - Schedule of Accounts Receivables and Unbilled Revenue (Details) link:presentationLink link:calculationLink link:definitionLink 9954719 - Disclosure - Accounts receivable, unbilled revenue (contract assets) and unearned revenue or payments on account (contract liabilities) - Schedule of Unbilled Services and Unearned Revenue or Payments on Account (Details) link:presentationLink link:calculationLink link:definitionLink 9954720 - Disclosure - Accounts receivable, unbilled revenue (contract assets) and unearned revenue or payments on account (contract liabilities) - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9954720 - Disclosure - Accounts receivable, unbilled revenue (contract assets) and unearned revenue or payments on account (contract liabilities) - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9954721 - Disclosure - Goodwill - Schedule of Goodwill (Details) link:presentationLink link:calculationLink link:definitionLink 9954722 - Disclosure - Goodwill - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9954723 - Disclosure - Intangible assets (Details) link:presentationLink link:calculationLink link:definitionLink 9954724 - Disclosure - Fair value measurements - Measurement of Fair Value of Major Asset and Liability classed (Details) link:presentationLink link:calculationLink link:definitionLink 9954725 - Disclosure - Fair value measurements - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9954726 - Disclosure - Restructuring - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9954727 - Disclosure - Restructuring - Summary of Restructuring Charges (Details) link:presentationLink link:calculationLink link:definitionLink 9954728 - Disclosure - Restructuring - Summary of Details of Movement in Restructuring Charges (Details) link:presentationLink link:calculationLink link:definitionLink 9954729 - Disclosure - Operating leases - Schedule of Lease Costs (Details) link:presentationLink link:calculationLink link:definitionLink 9954730 - Disclosure - Operating leases - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9954731 - Disclosure - Operating leases - Schedule of Operating Lease Maturity (Details) link:presentationLink link:calculationLink link:definitionLink 9954731 - Disclosure - Operating leases - Schedule of Operating Lease Maturity (Details) link:presentationLink link:calculationLink link:definitionLink 9954732 - Disclosure - Bank credit lines and loan facilities - Schedule of Outstanding Debt (Details) link:presentationLink link:calculationLink link:definitionLink 9954733 - Disclosure - Bank credit lines and loan facilities - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9954734 - Disclosure - Bank credit lines and loan facilities - Schedule of Contractual Maturities of Debt (Details) link:presentationLink link:calculationLink link:definitionLink 9954735 - Disclosure - Derivatives - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9954736 - Disclosure - Derivatives - Effect of Derivative Financial Instruments on Statement of Financial Position (Details) link:presentationLink link:calculationLink link:definitionLink 9954737 - Disclosure - Income taxes - Components of Tax (Details) link:presentationLink link:calculationLink link:definitionLink 9954738 - Disclosure - Income taxes - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9954739 - Disclosure - Net income per ordinary share - Schedule of Reconciliation of Number of Shares Used in Computation of Basic and Diluted Net Income Per Ordinary Share (Details) link:presentationLink link:calculationLink link:definitionLink 9954740 - Disclosure - Net income per ordinary share - Schedule of Reconciliation of Net Income Attributable to the Group (Details) link:presentationLink link:calculationLink link:definitionLink 9954741 - Disclosure - Share-based awards - Summary of Stock Option Activity (Details) link:presentationLink link:calculationLink link:definitionLink 9954742 - Disclosure - Share-based awards - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9954743 - Disclosure - Share-based awards - Schedule of Weighted Average Fair Values and Assumptions Used (Details) link:presentationLink link:calculationLink link:definitionLink 9954744 - Disclosure - Share-based awards - Summary of RSU and PSU Activity (Details) link:presentationLink link:calculationLink link:definitionLink 9954745 - Disclosure - Share-based awards - Schedule of Non-cash Stock Compensation Expense (Details) link:presentationLink link:calculationLink link:definitionLink 9954746 - Disclosure - Share capital (Details) link:presentationLink link:calculationLink link:definitionLink 9954747 - Disclosure - Business Segment and Geographical Information - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9954748 - Disclosure - Business Segment and Geographical Information - Schedule of Distribution of Revenue by Geographical Area (Details) link:presentationLink link:calculationLink link:definitionLink 9954749 - Disclosure - Business Segment and Geographical Information - Schedule of Distribution of Income from Operations by Geographical Area (Details) link:presentationLink link:calculationLink link:definitionLink 9954750 - Disclosure - Business Segment and Geographical Information - Schedule of Distribution of Depreciation and Amortization by Geographical Area (Details) link:presentationLink link:calculationLink link:definitionLink