Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Operating revenues and earnings (losses) from unconsolidated affiliates:
Total operating revenues	$ 524,165	$ 438,352	$ 1,474,009	$ 1,690,647
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted operating income (loss)	(15,093)	(64,931)	(77,097)	(102,720)
Investment income (loss)	200	(742)	1,401	(1,904)
Interest expense	(42,217)	(52,403)	(126,906)	(158,331)
Impairments and other charges	(3,068)	(5,017)	(65,419)	(339,303)
Other, net	(19,690)	425	(31,140)	48,330
Income (loss) from continuing operations before income taxes	(112,918)	(150,377)	(397,206)	(640,475)
ASSETS
Total assets	5,174,826		5,174,826		$ 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)	(15,093)	(64,931)	(77,097)	(102,720)
Other reconciling items
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted operating income (loss)	(33,050)	(27,709)	(98,045)	(86,547)
ASSETS
Total assets	768,932		768,932		443,153
U.S. Drilling
Operating revenues and earnings (losses) from unconsolidated affiliates:
Total operating revenues	173,441	130,243	477,346	578,928
U.S. Drilling | Operating segment
Operating revenues and earnings (losses) from unconsolidated affiliates:
Total operating revenues	173,441	130,243	477,346	578,928
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted operating income (loss)	(19,700)	(39,162)	(63,905)	(69,961)
ASSETS
Total assets	1,675,517		1,675,517		1,871,008
Canada Drilling
Operating revenues and earnings (losses) from unconsolidated affiliates:
Total operating revenues	6,034	10,774	39,336	39,929
Canada Drilling | Operating segment
Operating revenues and earnings (losses) from unconsolidated affiliates:
Total operating revenues	6,034	10,774	39,336	39,929
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted operating income (loss)	1,371	(3,507)	2,670	(9,265)
ASSETS
Total assets	11,468		11,468		174,123
International Drilling
Operating revenues and earnings (losses) from unconsolidated affiliates:
Total operating revenues	270,008	248,392	772,128	886,580
International Drilling | Operating segment
Operating revenues and earnings (losses) from unconsolidated affiliates:
Total operating revenues	270,008	248,392	772,128	886,580
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted operating income (loss)	(7,297)	(16,872)	(34,368)	(20,743)
ASSETS
Total assets	2,442,054		2,442,054		2,688,912
Drilling Solutions
Operating revenues and earnings (losses) from unconsolidated affiliates:
Total operating revenues	45,880	29,324	120,697	117,837
Drilling Solutions | Operating segment
Operating revenues and earnings (losses) from unconsolidated affiliates:
Total operating revenues	45,880	29,324	120,697	117,837
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted operating income (loss)	8,607	(3,583)	19,841	8,699
ASSETS
Total assets	76,041		76,041		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)	1,926	$ (1,807)	(1,335)	$ (11,450)
ASSETS
Total assets	$ 200,814		$ 200,814		$ 225,954