Supplemental Cash Flow Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Supplemental cash flow information:
Interest paid, net of capitalized interest	$ 154,127	$ 137,001
Income taxes paid	75	142
Capitalized interest	4,111	6,683
Supplemental schedule of non-cash investing activities:
Accrued construction costs	15,029	14,589
Supplemental schedule of non-cash financing activities:
Preferred stock redemption accrual		296,896
Vesting of restricted stock units	17	314
Cancellation of restricted stock	(6)	(1)
Conversion of non-managing member units into common stock	2,179	1,034
Mortgages and other liabilities assumed with real estate acquisitions	12,728
Unrealized gains on available-for-sale securities and derivatives designated as cash flow hedges, net	$ 6,675	$ 1,580