Assets Held for Sale and Discontinued Operations (Details2) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Nov. 30, 2018
Discontinued operations
Undiscounted contractual commitments	$ 2,400				$ 11,200				$ 2,400	$ 11,200
Liability related to discontinued operation					8,500					8,500
Current liability to discontinued operations	2,445				6,074				2,445	6,074
Operating revenues
Operating revenues									4,078	6,169	$ 2,859
Income (loss) from Oil & Gas discontinued operations:
Income (loss) from Oil and Gas discontinued operations, net of tax	(71)	$ (13,933)	$ (584)	$ (75)	(442)	$ (27,134)	$ (15,504)	$ (439)	(14,663)	(43,519)	(18,363)
Litigation expenses and reserves									9,939	1,273	3,936
Sale of business
Other long-term assets	$ 263,506				$ 252,854				263,506	252,854
Assets Held-for-sale
Income (loss) from Oil & Gas discontinued operations:
Impairment charge									17,000	35,300	15,400
Oil and Gas
Income (loss) from Oil & Gas discontinued operations:
Income (loss) from discontinued operations									(2,766)	(2,506)	(3,978)
Less: Impairment charges or other (gains) and losses on sale of wholly owned assets (2)									17,199	51,028	19,445
Less: Income tax expense (benefit)									(5,302)	(10,015)	(5,060)
Income (loss) from Oil and Gas discontinued operations, net of tax									$ (14,663)	(43,519)	$ (18,363)
Litigation expenses and reserves										$ 16,500
Oil and Gas | Canada Drilling | Assets Held-for-sale
Discontinued operations
Liability related to discontinued operation												$ 2,400