Income Taxes - Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of the differences between taxes on income (loss) before income taxes
Taxes (benefit) on U.S. and other international earnings (losses) at greater than the Bermuda rate	$ 49,375	$ (98,119)	$ (181,426)
Increase (decrease) in valuation allowance	38,822	29,165	17,865
Impact of Tax Reform Act		138,635
Tax reserves and interest	(10,626)	(148,615)	(3,468)
State income taxes (benefit)	1,698	(4,036)	(19,802)
Total income tax expense (benefit)	$ 79,269	$ (82,970)	$ (186,831)
Effective tax rate (as a percent)	(15.30%)	14.30%	15.60%
Additional interest expense for uncertain tax positions		$ 167,000
Effective income tax rate	21.00%	35.00%
Canada Drilling
Reconciliation of the differences between taxes on income (loss) before income taxes
Valuation allowance	$ 52,000
Office of the Tax Commissioner, Bermuda
Reconciliation of the differences between taxes on income (loss) before income taxes
Effective income tax rate	0.00%