Assets Held-for-Sale and Discontinued Operations (Details 2) (USD $)	3 Months Ended		6 Months Ended			3 Months Ended		6 Months Ended			3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Jun. 30, 2013 Oil and Gas	Jun. 30, 2012 Oil and Gas	Jun. 30, 2013 Oil and Gas	Jun. 30, 2012 Oil and Gas	Jul. 31, 2013 Oil and Gas United States	Jun. 30, 2013 Rig Services	Jun. 30, 2012 Rig Services	Jun. 30, 2013 Rig Services	Jun. 30, 2012 Rig Services	Apr. 02, 2013 Rig Services
Condensed Statements of Income
Operating revenues and Earnings (losses) from unconsolidated affiliates						$ 12,050,000	$ 2,919,000	$ 22,039,000	$ 6,220,000		$ 934,000	$ 5,554,000	$ 4,971,000	$ 10,416,000
Income (loss) from discontinued operations
Income (loss) from discontinued operations						(4,742,000)	(2,791,000)	(2,672,000)	(8,279,000)		6,905,000	(4,149,000)	9,823,000	(5,505,000)
Impairment charges or other gains and losses on sale of assets						(40,193,000)	41,597,000	(42,193,000)	36,468,000		1,382,000	(5,283,000)	1,129,000	(5,256,000)
Less: income tax expense (benefit)						(10,715,000)	7,042,000	(10,692,000)	4,227,000		2,071,000	(2,358,000)	2,737,000	(2,694,000)
Income (loss) from discontinued operations, net of tax	(28,004,000)	24,690,000	(25,958,000)	15,895,000		(34,220,000)	31,764,000	(34,173,000)	23,962,000		6,216,000	(7,074,000)	8,215,000	(8,067,000)
Sale of business
Sale price										90,000,000					9,300,000
Undiscounted contractual commitments	290,000,000		290,000,000
Liability related to discontinue operation	177,000,000		177,000,000		206,000,000
Current liability to discontinued operations	$ 57,737,000		$ 57,737,000		$ 68,961,000