Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Total revenues	$ 980,644	$ 1,083,215	$ 1,485,746
Operating expenses:
Depreciation	355,596	331,789	348,695
General and administrative	67,878	85,351	74,505
Impairment of assets		27,225	99,313
Restructuring and separation costs		5,041	14,146
Loss (gain) on disposition of assets	1,072	241	(10,500)
Total operating expenses	1,262,974	1,195,398	1,361,867
Operating (loss) income	(282,330)	(112,183)	123,879
Other income (expense):
Interest income	6,382	8,477	2,473
Interest expense, net of amounts capitalized	(122,832)	(123,240)	(113,528)
Loss on extinguishment of senior notes			(35,366)
Foreign currency transaction loss	(3,936)	(379)	(1,128)
Other, net	702	700	2,230
Loss before income tax benefit	(402,014)	(226,625)	(21,440)
Income tax benefit	44,800	46,353	39,786
Net (loss) income	$ (357,214)	$ (180,272)	$ 18,346
(Loss) earnings per share:
Basic	$ (2.60)	$ (1.31)	$ 0.13
Diluted	$ (2.60)	$ (1.31)	$ 0.13
Weighted-average shares outstanding:
Shares of common stock	137,652	137,399	137,213
Dilutive potential shares of common stock			52
Total weighted-average shares outstanding	137,652	137,399	137,265
Contract Drilling [Member]
Revenues:
Total revenues	$ 934,934	$ 1,059,973	$ 1,451,219
Operating expenses:
Contract drilling, excluding depreciation	793,412	722,834	801,964
Reimbursable Expenses [Member]
Revenues:
Total revenues	45,710	23,242	34,527
Operating expenses:
Contract drilling, excluding depreciation	$ 45,016	$ 22,917	$ 33,744