Real Estate (Details 2) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) property	Jun. 30, 2014 USD ($)
Properties acquired | property			1
Property Units Acquired			202
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	$ 136,243		$ 136,243
Disposed Properties | property			6
Disposed Units			1,377
Proceeds From Sale Of Property			$ 386,662
Net gain on sales of real estate properties	148,802	$ 14,903	$ 228,753	$ 14,903
Consolidated Rental Properties [Member]
Properties acquired | property			1
Property Units Acquired			202
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	130,275		$ 130,275
Disposed Properties | property			6
Disposed Units			1,377
Proceeds From Sale Of Property			$ 386,662
Land [Member]
Land parcels acquired | property			1
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	$ 5,968		$ 5,968
Commercial Real Estate [Member]
Proceeds From Sale Of Property			$ 123,300