Assets Held for Sale and Discontinued Operations (Details 2) - USD ($)	1 Months Ended	3 Months Ended								12 Months Ended
	Oct. 31, 2013	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Apr. 30, 2013
Discontinued operations
Undiscounted contractual commitments		$ 23,300,000				$ 84,600,000				$ 23,300,000	$ 84,600,000
Liability related to discontinued operation		16,100,000				40,200,000				16,100,000	40,200,000
Current liability to discontinued operations		5,197,000				19,602,000				5,197,000	19,602,000
Income (loss) from discontinued operations
Income (loss) from discontinued operations, net of tax		(1,730,000)	$ (45,275,000)	$ 5,025,000	$ (817,000)	(4,467,000)	$ 4,005,000	$ (1,032,000)	$ 1,515,000	(42,797,000)	21,000	$ (11,179,000)
Long-term deferred income taxes		29,326,000				443,003,000				29,326,000	443,003,000
Net noncurrent deferred asset		184,865,000				30,961,000				184,865,000	30,961,000
Cash proceeds from sale of businesses in Alaska											35,100,000
Receivables held for sale						27,000,000					27,000,000
Proceed from sale of working interest											600,000,000
Sale of business
Gain on sale of oil and gas operations											22,200,000
Other long-term assets		452,305,000				$ 289,745,000				452,305,000	289,745,000
Assets Held-for-sale
Income (loss) from discontinued operations
Impairment charge										51,000,000
Impairment of note receivable										3,100,000
Oil and Gas
Operating revenues
Operating revenues										3,212,000	13,143,000	25,327,000
Income (loss) from discontinued operations
Income (loss) from discontinued operations										(5,003,000)	(1,840,000)	(17,371,000)
Less: Impairment charges or other (gains) and losses on sale of wholly owned assets and obligations										49,890,000	(1,313,000)	24,087,000
Less: Income tax expense (benefit)										(14,455,000)	(548,000)	(14,062,000)
Income (loss) from discontinued operations, net of tax										(40,438,000)	21,000	(27,396,000)
Write down of carrying value of assets offset by gain of future pipeline obligations											$ 61,500,000
Gross cash proceeds												90,000,000
Oil and Gas | CANADA
Income (loss) from discontinued operations
Long-term deferred income taxes		6,300,000								6,300,000
Rig Services
Operating revenues
Operating revenues												127,154,000
Income (loss) from discontinued operations
Income (loss) from discontinued operations												17,680,000
Less: Impairment charges or other (gains) and losses on sale of wholly owned assets and obligations										3,146,000		(4,368,000)
Less: Income tax expense (benefit)										(787,000)		5,831,000
Income (loss) from discontinued operations, net of tax										(2,359,000)		$ 16,217,000
Sale price													$ 9,300,000
Sale of business
Other long-term assets		$ 16,400,000								$ 16,400,000
Rig Services | Peak
Income (loss) from discontinued operations
Cash proceeds from sale of businesses in Alaska	$ 135,500,000