Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues:
Total revenues	$ 254,020	$ 286,322	$ 704,268	$ 850,693
Operating expenses:
Depreciation	88,693	81,884	263,844	245,534
General and administrative	18,830	33,308	51,436	70,057
Impairment of assets				27,225
Restructuring and separation costs		649		4,925
Loss (gain) on disposition of assets	6,340	(506)	1,191	(1,066)
Total operating expenses	326,854	309,365	937,729	925,599
Operating loss	(72,834)	(23,043)	(233,461)	(74,906)
Other income (expense):
Interest income	1,317	2,364	5,664	6,001
Interest expense, net of amounts capitalized	(31,098)	(34,293)	(92,182)	(92,196)
Foreign currency transaction (loss) gain	(77)	(743)	(1,883)	115
Other, net	82	(179)	520	664
Loss before income tax benefit	(102,610)	(55,894)	(321,342)	(160,322)
Income tax benefit	7,482	4,782	38,898	59,257
Net loss	$ (95,128)	$ (51,112)	$ (282,444)	$ (101,065)
Loss per share, Basic and Diluted	$ (0.69)	$ (0.37)	$ (2.05)	$ (0.74)
Weighted-average shares outstanding:
Shares of common stock	137,694	137,434	137,636	137,386
Total weighted-average shares outstanding	137,694	137,434	137,636	137,386
Contract Drilling [Member]
Revenues:
Total revenues	$ 242,315	$ 280,691	$ 676,284	$ 833,970
Operating expenses:
Contract drilling, excluding depreciation	201,568	188,456	593,779	562,466
Reimbursable Expenses [Member]
Revenues:
Total revenues	11,705	5,631	27,984	16,723
Operating expenses:
Contract drilling, excluding depreciation	$ 11,423	$ 5,574	$ 27,479	$ 16,458