Segment Information (Details 1) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010
Segment Reporting Information [Line Items]
Equity in (earnings) losses of unconsolidated affiliates, net of dividends			$ 135,844,000	$ 14,494,000
Investments in unconsolidated affiliates accounted for using equity method	320,500,000		320,500,000		265,800,000
Segment Information (Textuals) [Abstract]
Investments in unconsolidated affiliates accounted for using cost method	2,500,000		2,500,000		1,900,000
Oil and Gas [Member]
Segment Reporting Information [Line Items]
Equity in (earnings) losses of unconsolidated affiliates, net of dividends	34,900,000	6,800,000	56,300,000	14,500,000
Investments in unconsolidated affiliates accounted for using equity method	234,600,000		234,600,000		146,500,000
Subtotal Contract Drilling [Member]
Segment Reporting Information [Line Items]
Equity in (earnings) losses of unconsolidated affiliates, net of dividends	(900,000)	600,000	3,000,000	3,700,000
Investments in unconsolidated affiliates accounted for using equity method	57,900,000		57,900,000		54,800,000
Other Operating Segments [Member]
Segment Reporting Information [Line Items]
Equity in (earnings) losses of unconsolidated affiliates, net of dividends	(300,000)	4,400,000	0	10,100,000
Investments in unconsolidated affiliates accounted for using equity method	$ 28,000,000		$ 28,000,000		$ 64,500,000