Segment Information (Details 1) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Segment Reporting Information [Line Items]
Equity in (earnings) losses of unconsolidated affiliates, net of dividends			$ 102,122,000	$ 10,379,000
Investments in unconsolidated affiliates accounted for using equity method	301,400,000		301,400,000		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	6,200,000	3,200,000	21,400,000	7,700,000
Investments in unconsolidated affiliates accounted for using equity method	178,000,000		178,000,000		146,500,000
Subtotal Contract Drilling [Member]
Segment Reporting Information [Line Items]
Equity in (earnings) losses of unconsolidated affiliates, net of dividends	3,700,000	2,900,000	3,900,000	3,000,000
Investments in unconsolidated affiliates accounted for using equity method	58,700,000		58,700,000		54,800,000
Other Operating Segments [Member]
Segment Reporting Information [Line Items]
Equity in (earnings) losses of unconsolidated affiliates, net of dividends	(600,000)	2,700,000	300,000	5,800,000
Investments in unconsolidated affiliates accounted for using equity method	$ 64,700,000		$ 64,700,000		$ 64,500,000