Taxation	3 Months Ended
Mar. 31, 2018
Income Tax Disclosure [Abstract]
Taxation	Taxation For the three months ended March 31, 2018, the effective tax rate on income from continuing operations was 7% (2017: 2%). The effective tax rate for the three months ended March 31, 2018 has been affected by certain provisions of the U.S. Tax Cuts and Jobs Act (Tax Act) passed in December 2017, which enacts a U.S. federal tax rate of 21% along with anti-deferral provisions and new limitations on certain deductions required under the Tax Act. Due to enactment late in the Company’s annual 2017 reporting period, the Company included the provisional amounts in its annual financial statements for the year ended December 31, 2017. The Company continued to assess the impact of the Tax Act during the three months ended March 31, 2018 and recorded an adjustment of $22.0 million to its provisional estimate related to the remeasurement of deferred tax assets and liabilities. This remeasurement reduced the effective tax rate for the three months ended March 31, 2018 by 3%. It is expected that additional interpretive guidance will be issued that may change how the Company has computed the provisional amounts for the year ended December 31, 2017. The Company will continue to assess the impact of the Tax Act during the measurement period and will record any adjustments to its provisional estimates as needed during the remainder of 2018 and continues to assert that all amounts recorded and disclosed to date remain provisional. Certain discrete events occurred during Q1 2017 which contributed to the low effective tax rate, including the recording of a net tax benefit related to prior year tax reserves.

Taxation

For the three months ended March 31, 2018, the effective tax rate on income from continuing operations was 7% (2017: 2%).

The effective tax rate for the three months ended March 31, 2018 has been affected by certain provisions of the U.S. Tax Cuts and Jobs Act (Tax Act) passed in December 2017, which enacts a U.S. federal tax rate of 21% along with anti-deferral provisions and new limitations on certain deductions required under the Tax Act. Due to enactment late in the Company’s annual 2017 reporting period, the Company included the provisional amounts in its annual financial statements for the year ended December 31, 2017. The Company continued to assess the impact of the Tax Act during the three months ended March 31, 2018 and recorded an adjustment of $22.0 million to its provisional estimate related to the remeasurement of deferred tax assets and liabilities. This remeasurement reduced the effective tax rate for the three months ended March 31, 2018 by 3%.

It is expected that additional interpretive guidance will be issued that may change how the Company has computed the provisional amounts for the year ended December 31, 2017. The Company will continue to assess the impact of the Tax Act during the measurement period and will record any adjustments to its provisional estimates as needed during the remainder of 2018 and continues to assert that all amounts recorded and disclosed to date remain provisional.

Certain discrete events occurred during Q1 2017 which contributed to the low effective tax rate, including the recording of a net tax benefit related to prior year tax reserves.