Equity Accumulated Other Comprehensive Income Schedule (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Balance at beginning of period	$ (82,991)		$ (89,180)
Other comprehensive income before reclassifications	(1,859)		(5,854)
Amounts reclassified from accumulated other comprehensive income (1)	8,894	[1]	15,916	[1]
Net current period other comprehensive income	7,035		10,062
Less other comprehensive income attributable to noncontrolling interests	(1,942)		(3,625)
Other comprehensive income attributable to common stockholders	5,093		6,437
Accumulated other comprehensive income at end of period	$ (77,898)		$ (82,743)

[1] Cash flow hedge adjustments