Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reserves for uncertain tax positions	$ 159,669	$ 183,786
Related tax benefits	400	1,008	$ 1,008
Amount provision for income taxes reduced if reserves not realized	159,700
Interest and penalties resulted in an income tax expense	3,000	5,100	$ 4,700
Provision for non-cash items related to impairment of three rigs	2,600	$ 35,600
Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimate potential changes ranges	80,000
Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimate potential changes ranges	100,000
UK income tax
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Interest and penalties resulted in an income tax expense	$ 36,800
Statutory rate	19.00%
2010 and 2011
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Income tax benefit included net discrete tax benefit	$ (33,700)
2005 and 2008
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Income tax benefit included net discrete tax benefit	$ (5,200)