Property and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 10,924,509		$ 10,924,509		$ 12,034,331
Loss on impairment	792,843	$ 0	792,843	$ 0
Drilling equipment and facilities
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	10,610,440		10,610,440		11,746,629
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	111,304		111,304		83,509
Other
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 202,765		$ 202,765		$ 204,193