Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues:
Total revenues	$ 233,542	$ 295,510
Operating expenses:
Depreciation	86,898	81,825
General and administrative	17,312	18,513
Restructuring and separation costs		3,011
Loss (gain) on disposition of assets	4,287	(510)
Total operating expenses	282,669	294,998
Operating (loss) income	(49,127)	512
Other income (expense):
Interest income	2,414	1,637
Interest expense, net of amounts capitalized	(29,925)	(28,318)
Foreign currency transaction (loss) gain	(1,085)	447
Other, net	333	580
Loss before income tax benefit	(77,390)	(25,142)
Income tax benefit	4,062	44,463
Net (loss) income	$ (73,328)	$ 19,321
(Loss) Earnings per share, Basic and Diluted	$ (0.53)	$ 0.14
Weighted-average shares outstanding:
Shares of common stock	137,522,000	137,294,000
Dilutive potential shares of common stock		201,000
Total weighted-average shares outstanding	137,522,000	137,495,000
Contract Drilling [Member]
Revenues:
Total revenues	$ 226,697	$ 287,926
Operating expenses:
Contract drilling, excluding depreciation	167,429	184,689
Reimbursable Expenses [Member]
Revenues:
Total revenues	6,845	7,584
Operating expenses:
Contract drilling, excluding depreciation	$ 6,743	$ 7,470