Income Taxes	9 Months Ended
Sep. 30, 2016
Components of Income Tax Expense (Benefit), Continuing Operations [Abstract]
Income Taxes	Income Taxes Our consolidated effective income tax rate for the three-month and nine-month periods ended September 30, 2016, excluding the impact of discrete tax items, was 6.0% and 21.9%, respectively. Discrete tax items for the three-month and nine-month period ended September 30, 2016 were primarily attributable to the gain on debt extinguishment, changes in liabilities for unrecognized tax benefits associated with tax positions taken in prior years and other resolutions of prior year tax matters. Discrete tax items for the nine-month period ended September 30, 2016 also resulted from restructuring transactions involving certain of our subsidiaries. Our consolidated effective income tax rate for the three-month and nine-month periods ended September 30, 2015 excluding the impact of discrete tax items, was 12.6% and 16.4%, respectively. Discrete tax items for the three-month and nine-month periods were primarily attributable to the early termination of the ENSCO DS-4 drilling contract and the recognition of liabilities for unrecognized tax benefits associated with tax positions taken in prior years. The changes in our consolidated effective tax rate, excluding discrete items, for the three-month and nine-month periods ended September 30, 2016 as compared to the prior year period is primarily attributable to changes in the relative components of our estimated 2016 earnings, excluding discrete items, generated in tax jurisdictions with higher tax rates and to the impact of 2016 restructuring transactions involving certain of our subsidiaries.

Income Taxes

9 Months Ended

Sep. 30, 2016

Components of Income Tax Expense (Benefit), Continuing Operations [Abstract]

Our consolidated effective income tax rate for the three-month and nine-month periods ended September 30, 2016, excluding the impact of discrete tax items, was 6.0% and 21.9%, respectively. Discrete tax items for the three-month and nine-month period ended September 30, 2016 were primarily attributable to the gain on debt extinguishment, changes in liabilities for unrecognized tax benefits associated with tax positions taken in prior years and other resolutions of prior year tax matters. Discrete tax items for the nine-month period ended September 30, 2016 also resulted from restructuring transactions involving certain of our subsidiaries.

Our consolidated effective income tax rate for the three-month and nine-month periods ended September 30, 2015 excluding the impact of discrete tax items, was 12.6% and 16.4%, respectively. Discrete tax items for the three-month and nine-month periods were primarily attributable to the early termination of the ENSCO DS-4 drilling contract and the recognition of liabilities for unrecognized tax benefits associated with tax positions taken in prior years.

The changes in our consolidated effective tax rate, excluding discrete items, for the three-month and nine-month periods ended September 30, 2016 as compared to the prior year period is primarily attributable to changes in the relative components of our estimated 2016 earnings, excluding discrete items, generated in tax jurisdictions with higher tax rates and to the impact of 2016 restructuring transactions involving certain of our subsidiaries.