Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Operating revenues and earnings (losses) from unconsolidated affiliates:
Total operating revenues	$ 489,333	$ 533,931	$ 949,844	$ 1,252,295
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted operating income (loss)	(26,084)	(28,673)	(62,004)	(37,789)
Investment income (loss)	(62)	2,036	1,201	(1,162)
Interest expense	(41,714)	(51,206)	(84,689)	(105,928)
Impairments and other charges	(59,868)	(57,852)	(62,351)	(334,286)
Other, net	(6,587)	30,795	(11,450)	47,905
Income (loss) from continuing operations before income taxes	(165,684)	(133,522)	(284,288)	(490,098)
ASSETS
Total assets	5,042,318		5,042,318		$ 5,503,428
Operating segment
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted operating income (loss)	(26,084)	(28,673)	(62,004)	(37,789)
Other reconciling items
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted operating income (loss)	(31,369)	(28,622)	(64,995)	(58,838)
ASSETS
Total assets	423,070		423,070		443,153
U.S. Drilling
Operating revenues and earnings (losses) from unconsolidated affiliates:
Total operating revenues	161,606	173,784	303,905	448,685
U.S. Drilling | Operating segment
Operating revenues and earnings (losses) from unconsolidated affiliates:
Total operating revenues	161,606	173,784	303,905	448,685
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted operating income (loss)	(20,869)	(23,395)	(44,205)	(30,799)
ASSETS
Total assets	1,724,672		1,724,672		1,871,008
Canada Drilling
Operating revenues and earnings (losses) from unconsolidated affiliates:
Total operating revenues	12,313	3,564	33,302	29,155
Canada Drilling | Operating segment
Operating revenues and earnings (losses) from unconsolidated affiliates:
Total operating revenues	12,313	3,564	33,302	29,155
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted operating income (loss)	(2,608)	(5,795)	1,299	(5,758)
ASSETS
Total assets	109,437		109,437		174,123
International Drilling
Operating revenues and earnings (losses) from unconsolidated affiliates:
Total operating revenues	255,282	301,078	502,120	638,188
International Drilling | Operating segment
Operating revenues and earnings (losses) from unconsolidated affiliates:
Total operating revenues	255,282	301,078	502,120	638,188
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted operating income (loss)	(8,439)	276	(27,071)	(3,871)
ASSETS
Total assets	2,493,823		2,493,823		2,688,912
Drilling Solutions
Operating revenues and earnings (losses) from unconsolidated affiliates:
Total operating revenues	39,111	33,129	74,817	88,513
Drilling Solutions | Operating segment
Operating revenues and earnings (losses) from unconsolidated affiliates:
Total operating revenues	39,111	33,129	74,817	88,513
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted operating income (loss)	6,524	1,733	11,234	12,282
ASSETS
Total assets	82,705		82,705		100,278
Rig Technologies | Operating segment
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted operating income (loss)	(692)	$ (1,492)	(3,261)	$ (9,643)
ASSETS
Total assets	$ 208,611		$ 208,611		$ 225,954