Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues
Contract drilling	$ 38,910	$ 76,415	$ 128,343	$ 142,331
Revenue, Product and Service [Extensible List]	us-gaap:OilAndGasServiceMember	us-gaap:OilAndGasServiceMember	us-gaap:OilAndGasServiceMember	us-gaap:OilAndGasServiceMember
Costs and expenses
Operating expenses	$ 61,854	$ 52,254	$ 148,329	$ 104,550
General and administrative expenses	10,857	10,010	20,500	21,256
Depreciation and amortization expense	26,811	59,330	53,742	118,229
Loss from unconsolidated subsidiaries		700		2,024
Total costs and expenses	99,522	122,294	222,571	246,059
Operating loss	(60,612)	(45,879)	(94,228)	(103,728)
Other income (expense)
Interest expense	(26,607)	(24,406)	(51,734)	(48,445)
Reorganization items	(248)	(878)	(362)	(1,881)
Interest income	520	1,665	1,327	3,637
Other income (expense)	1	(220)	(212)	(311)
Loss before income taxes	(86,946)	(69,718)	(145,209)	(150,728)
Income tax expense	452	3,868	3,152	6,837
Net loss	$ (87,398)	$ (73,586)	$ (148,361)	$ (157,565)
Loss per common share, basic (in dollars per share)	$ (1.16)	$ (0.98)	$ (1.97)	$ (2.10)
Weighted-average shares outstanding, basic	75,199	75,001	75,191	75,016
Loss per common share, diluted (in dollars per share)	$ (1.16)	$ (0.98)	$ (1.97)	$ (2.10)
Weighted-average shares outstanding, diluted	75,199	75,001	75,191	75,016