Segment Information (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) segment	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Financial information with respect to reportable segments
Number of reportable segments | segment									5
Operating revenues and earnings (losses) from unconsolidated affiliates:
Total operating revenues	$ 714,261	$ 758,076	$ 771,406	$ 799,640	$ 782,080	$ 779,425	$ 761,920	$ 734,194	$ 3,043,383	$ 3,057,619	$ 2,564,285
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted income (loss) derived from operating activities									89,145	58,621	(141,937)
Earnings (losses) from unconsolidated affiliates									(5)	1	7
Investment income (loss)									10,218	(9,499)	1,194
Interest expense									(204,311)	(227,124)	(222,889)
Impairments and other charges									(290,471)	(144,446)	(44,536)
Other, net									(33,224)	(29,532)	(14,880)
Income (loss) from continuing operations before income taxes									(588,922)	(518,794)	(580,084)
ASSETS
Total assets (1)	6,760,658				7,853,944				6,760,658	7,853,944
Depreciation and amortization:
Depreciation and amortization									876,091	866,870	842,943
Capital expenditures and acquisitions of businesses
Capital expenditures									423,967	453,435	539,191
Operating segment
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted income (loss) derived from operating activities									89,145	58,621	(141,937)
Operating segment | U.S. Drilling
Operating revenues and earnings (losses) from unconsolidated affiliates:
Total operating revenues									1,240,936	1,083,227	805,223
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted income (loss) derived from operating activities									64,313	(21,298)	(213,877)
ASSETS
Total assets (1)	2,369,200				2,982,974				2,369,200	2,982,974
Depreciation and amortization:
Depreciation and amortization									419,680	394,586	375,171
Capital expenditures and acquisitions of businesses
Capital expenditures									184,705	222,338	330,875
Operating segment | Canada Drilling
Operating revenues and earnings (losses) from unconsolidated affiliates:
Total operating revenues									68,274	105,000	82,929
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted income (loss) derived from operating activities									(14,483)	(6,166)	(22,262)
ASSETS
Total assets (1)	202,706				252,817				202,706	252,817
Depreciation and amortization:
Depreciation and amortization									29,766	37,172	39,597
Capital expenditures and acquisitions of businesses
Capital expenditures									5,020	12,981	17,197
Operating segment | International Drilling
Operating revenues and earnings (losses) from unconsolidated affiliates:
Total operating revenues									1,324,142	1,469,038	1,474,060
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted income (loss) derived from operating activities									(8,903)	74,221	108,428
ASSETS
Total assets (1)	2,979,494				3,320,347				2,979,494	3,320,347
Depreciation and amortization:
Depreciation and amortization									372,883	383,227	400,753
Capital expenditures and acquisitions of businesses
Capital expenditures									209,728	172,565	159,817
Operating segment | Drilling Solutions
Operating revenues and earnings (losses) from unconsolidated affiliates:
Total operating revenues									252,790	250,242	140,701
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted income (loss) derived from operating activities									59,465	37,626	16,738
ASSETS
Total assets (1)	218,004				281,078				218,004	281,078
Depreciation and amortization:
Depreciation and amortization									32,289	31,037	16,188
Capital expenditures and acquisitions of businesses
Capital expenditures									23,598	30,709	35,617
Operating segment | Rig Technologies
Operating revenues and earnings (losses) from unconsolidated affiliates:
Total operating revenues									260,226	270,988	234,542
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted income (loss) derived from operating activities									(11,247)	(25,762)	(30,964)
ASSETS
Total assets (1)	324,523				401,044				324,523	401,044
Depreciation and amortization:
Depreciation and amortization									12,715	16,387	11,530
Capital expenditures and acquisitions of businesses
Capital expenditures									6,592	12,250	4,715
Other reconciling items (1)
Operating revenues and earnings (losses) from unconsolidated affiliates:
Total operating revenues									(102,985)	(120,876)	(173,170)
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted income (loss) derived from operating activities									(160,274)	(166,815)	(157,043)
ASSETS
Total assets (1)	$ 666,731				$ 615,684				666,731	615,684
Depreciation and amortization:
Depreciation and amortization									8,758	4,461	(296)
Capital expenditures and acquisitions of businesses
Capital expenditures									$ (5,676)	$ 2,592	$ (9,030)