Assets Held-for-Sale and Discontinued Operations (Details 2) (USD $)	3 Months Ended			3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012	Mar. 31, 2013 Oil and Gas	Mar. 31, 2012 Oil and Gas	Mar. 31, 2013 Rig Services	Mar. 31, 2012 Rig Services	Apr. 02, 2013 Rig Services
Condensed Statements of Income
Operating revenues and Earnings (losses) from unconsolidated affiliates				$ 9,989,000	$ 3,301,000	$ 4,037,000	$ 4,862,000
Income (loss) from discontinued operations
Income (loss) from discontinued operations				2,070,000	(5,488,000)	2,918,000	(1,356,000)
Impairment charges or other gains and losses on sale of assets				(2,000,000)	(5,129,000)	(253,000)	27,000
Less: income tax expense (benefit)				23,000	(2,815,000)	666,000	(336,000)
Income (loss) from discontinued operations, net of tax	2,046,000	(8,795,000)		47,000	(7,802,000)	1,999,000	(993,000)
Sale of business
Sale price								9,300,000
Undiscounted contractual commitments	321,900,000
Liability related to discontinue operation	192,600,000		206,000,000
Current liability related to discontinue operation	$ 60,291,000		$ 68,961,000