Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Supplemental cash flow information:
Interest paid, net of capitalized interest	$ 217,716	$ 204,590
Income taxes paid	2,920	3,380
Capitalized interest	3,704	5,983
Supplemental schedule of non-cash investing activities:
Accrued construction costs	33,162	25,069
Settlement of loans receivable as consideration for real estate acquisition	254,301
Supplemental schedule of non-cash financing activities:
Vesting of restricted stock units	379	567
Cancellation of restricted stock		(1)
Conversion of non-managing member units into common stock	2,244	73
Noncontrolling interest and other liabilities, net assumed in connection with the RIDEA III acquisition	61,219
Noncontrolling interest issued in connection with real estate acquisition	3,885	6,321
Noncontrolling interest disposed in connection with real estate sales	204	1,671
Other liabilities assumed with real estate acquisitions	13,672	523
Unrealized (losses) on available-for-sale securities and derivatives designated as cash flow hedges, net	$ (198)	$ (696)