Basis of Preparation (Policies)	6 Months Ended
Jun. 30, 2017
Accounting Policies [Abstract]
New Accounting Pronouncements Adopted in 2017 and Not Yet Adopted	Accounting Pronouncements Adopted in 2017 On March 30, 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-09, “Compensation — Stock Compensation” which provides guidance on several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. This ASU is effective for fiscal years beginning after December 15, 2016 and interim periods beginning after December 15, 2016. Following the adoption of this ASU, all excess tax benefits or expense related to stock-based compensation transactions are recognized prospectively as income tax benefits or expense in the Consolidated Income Statement and the excess tax benefits or expense from stock-based compensation transactions previously included in “Financing activities” on the Consolidated Statements of Cash Flows are prospectively included on that statement as “Operating activities.” The cash paid to the tax authority for tax withholding purposes has also been reclassified from operating to financing activity in the Consolidated Statement of Cash Flows and the comparative period has been restated. This ASU also allows share withholding up to the maximum statutory withholding requirement while still avoiding liability accounting. As a result, the Company has applied the equity accounting method for its restricted share units retrospectively and has recorded a cumulative effect adjustment of $2.8 million through opening retained earnings and $7.9 million through additional paid-in capital. Accounting Pronouncements Not Yet Adopted On March 10, 2017, FASB issued ASU 2017-7, “Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post Retirement Benefit Cost” which changes how employers report defined benefit pension and/or other post-retirement benefit costs in their financial statements. This ASU is effective for fiscal years beginning after December 15, 2017 and interim periods beginning after December 15, 2017. As the Company does not operate a defined benefit pension scheme, the impact from the adoption of the ASU is unlikely to have a material impact on future financial statements and disclosures. Other accounting pronouncements were issued during the three months ended June 30, 2017 which were either not relevant to the Company or did not impact the Company’s consolidated financial statements.

Accounting Pronouncements Adopted in 2017

On March 30, 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-09, “Compensation — Stock Compensation” which provides guidance on several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. This ASU is effective for fiscal years beginning after December 15, 2016 and interim periods beginning after December 15, 2016. Following the adoption of this ASU, all excess tax benefits or expense related to stock-based compensation transactions are recognized prospectively as income tax benefits or expense in the Consolidated Income Statement and the excess tax benefits or expense from stock-based compensation transactions previously included in “Financing activities” on the Consolidated Statements of Cash Flows are prospectively included on that statement as “Operating activities.” The cash paid to the tax authority for tax withholding purposes has also been reclassified from operating to financing activity in the Consolidated Statement of Cash Flows and the comparative period has been restated. This ASU also allows share withholding up to the maximum statutory withholding requirement while still avoiding liability accounting. As a result, the Company has applied the equity accounting method for its restricted share units retrospectively and has recorded a cumulative effect adjustment of $2.8 million through opening retained earnings and $7.9 million through additional paid-in capital.

Accounting Pronouncements Not Yet Adopted

On March 10, 2017, FASB issued ASU 2017-7, “Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post Retirement Benefit Cost” which changes how employers report defined benefit pension and/or other post-retirement benefit costs in their financial statements. This ASU is effective for fiscal years beginning after December 15, 2017 and interim periods beginning after December 15, 2017. As the Company does not operate a defined benefit pension scheme, the impact from the adoption of the ASU is unlikely to have a material impact on future financial statements and disclosures.

Other accounting pronouncements were issued during the three months ended June 30, 2017 which were either not relevant to the Company or did not impact the Company’s consolidated financial statements.