Mortgage Notes Payable, Unsecured Notes and Credit Facility (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Notes Payable, Unsecured Notes and Credit Facility
Total mortgage notes payable and unsecured notes	$ 7,054,852	$ 7,076,758
Credit Facility	0	0
Total mortgage notes payable, unsecured notes and Credit Facility	7,054,852	7,076,758
Unsecured notes
Notes Payable, Unsecured Notes and Credit Facility
Fixed rate notes	4,200,000	4,200,000
Total mortgage notes payable and unsecured notes	4,500,000
Amount of debt discount	8,640	8,930
Amount of deferred financing costs, net	26,814	27,768
Term Loans
Notes Payable, Unsecured Notes and Credit Facility
Variable rate notes	300,000	300,000
Secured notes
Notes Payable, Unsecured Notes and Credit Facility
Fixed rate notes	1,664,650	1,668,496
Variable rate notes	890,202	908,262
Total mortgage notes payable and unsecured notes	2,275,860
Amount of debt discount	3,044
Amount of deferred financing costs, net	$ 10,625	11,046
Amount of debt premium		$ (1,866)