Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues:
Contract drilling	$ 1,525,214	$ 2,360,184	$ 2,737,126
Revenues related to reimbursable expenses	75,128	59,209	77,545
Total revenues	1,600,342	2,419,393	2,814,671
Operating expenses:
Contract drilling, excluding depreciation	772,173	1,227,864	1,523,623
Reimbursable expenses	58,058	58,050	76,091
Depreciation	381,760	493,162	456,483
General and administrative	63,560	66,462	81,832
Impairment of assets	678,145	860,441	109,462
Bad debt recovery	(265)
Restructuring and separation costs		9,778
Loss (gain) on disposition of assets	3,795	(2,290)	(5,382)
Total operating expenses	1,957,226	2,713,467	2,242,109
Operating (loss) income	(356,884)	(294,074)	572,562
Other income (expense):
Interest income	768	3,322	801
Interest expense, net of amounts capitalized	(89,934)	(93,934)	(62,053)
Foreign currency transaction (loss) gain	(11,522)	2,465	3,199
Other, net	(10,727)	873	682
(Loss) income before income tax benefit (expense)	(468,299)	(381,348)	515,191
Income tax benefit (expense)	95,796	107,063	(128,180)
Net (loss) income	$ (372,503)	$ (274,285)	$ 387,011
(Loss) earnings per share:
Basic	$ (2.72)	$ (2.00)	$ 2.82
Diluted	$ (2.72)	$ (2.00)	$ 2.81
Weighted-average shares outstanding:
Shares of common stock	137,168	137,157	137,473
Dilutive potential shares of common stock			50
Total weighted-average shares outstanding	137,168	137,157	137,523
Cash dividends declared per share of common stock		$ 0.50	$ 3.50