Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019		Mar. 31, 2018	Dec. 31, 2018	[1]
Operating revenues and earnings (losses) from unconsolidated affiliates:
Operating revenues	$ 799,640		$ 734,194
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted income (loss) derived from operating activities	26,694		(57)
Earnings (losses) from unconsolidated affiliates	(5)		2
Investment income (loss)	9,677		465
Interest expense	(52,352)		(61,386)
Other, net	(17,502)		(14,089)
Income (loss) from continuing operations before income taxes	(73,577)		(120,042)
ASSETS
Total assets (1)	7,773,684	[1]	7,853,944	$ 7,853,944
U.S. Drilling
Operating revenues and earnings (losses) from unconsolidated affiliates:
Operating revenues	320,209		241,002
Canada Drilling
Operating revenues and earnings (losses) from unconsolidated affiliates:
Operating revenues	25,315		31,887
International Drilling
Operating revenues and earnings (losses) from unconsolidated affiliates:
Operating revenues	337,256		368,845
Drilling Solutions
Operating revenues and earnings (losses) from unconsolidated affiliates:
Operating revenues	65,422		62,648
Rig Technologies
Operating revenues and earnings (losses) from unconsolidated affiliates:
Operating revenues	71,753		64,669
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	26,694		(57)
Operating segment | U.S. Drilling
Operating revenues and earnings (losses) from unconsolidated affiliates:
Operating revenues	320,209		241,002
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted income (loss) derived from operating activities	24,683		(19,746)
ASSETS
Total assets (1)	2,954,828		2,982,974
Operating segment | Canada Drilling
Operating revenues and earnings (losses) from unconsolidated affiliates:
Operating revenues	25,315		31,887
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)		(592)
ASSETS
Total assets (1)	250,417		252,817
Operating segment | International Drilling
Operating revenues and earnings (losses) from unconsolidated affiliates:
Operating revenues	337,256		368,845
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted income (loss) derived from operating activities	(5,637)		24,536
ASSETS
Total assets (1)	3,243,297		3,320,347
Operating segment | Drilling Solutions
Operating revenues and earnings (losses) from unconsolidated affiliates:
Operating revenues	65,422		62,648
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted income (loss) derived from operating activities	12,855		8,721
ASSETS
Total assets (1)	269,329		281,078
Operating segment | Rig Technologies
Operating revenues and earnings (losses) from unconsolidated affiliates:
Operating revenues	71,753		64,669
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted income (loss) derived from operating activities	(5,148)		(12,976)
ASSETS
Total assets (1)	426,517		401,044
Other reconciling items (3)
Operating revenues and earnings (losses) from unconsolidated affiliates:
Operating revenues	20,315		34,857
Reconciliation of segment adjusted operating income (loss) to net income (loss) from continuing operations before income taxes:
Adjusted income (loss) derived from operating activities	(40,089)		(44,977)
ASSETS
Total assets (1)	$ 629,296		$ 615,684

[1] The condensed consolidated balance sheet as of March 31, 2019 and December 31, 2018 include assets and liabilities of variable interest entities. See Note 3—Joint Ventures for additional information.