Stockholder's Equity (Details 3) (USD $) In Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010		Sep. 30, 2011		Sep. 30, 2010
Summary of comprehensive income/(loss)
Unrecognized gain (losses) on cash flow hedges	$ 191		$ (2,975)		$ 1,059		$ (8,473)
Unrecognized gains (losses) on equity investments	(400)		42		(314)		(95)
Total other comprehensive income (loss)	(209)		(2,933)		745		(8,568)
Net income attributable to controlling interests	53,841		784		173,094		83,233
Comprehensive income (loss) attributable to controlling interests	53,632		(2,149)		173,839		74,665
Less: Net income (loss) attributable to noncontrolling interests	(1,488)	[1]	(690)	[1]	(2,721)	[1]	(383)	[1]
Total comprehensive income (loss)	$ 52,144		$ 2,839		$ 171,118		$ 74,282

[1] Includes amounts attributable to redeemable noncontrolling interests.