Notes Payable, Unsecured Notes and Credit Facility (Details) - USD ($) $ in Thousands		Mar. 31, 2016	Dec. 31, 2015
Notes Payable, Unsecured Notes and Credit Facility
Total notes payable and unsecured notes		$ 6,528,834	$ 6,481,291
Credit Facility		0	0
Total mortgage notes payable, unsecured notes and Credit Facility		6,528,834	6,481,291
Unsecured notes
Notes Payable, Unsecured Notes and Credit Facility
Fixed rate notes	[1]	3,575,000	3,575,000
Total notes payable and unsecured notes		3,875,000
Amount of debt discount		7,310	7,601
Deferred Finance Costs, Net		20,836	21,725
Term Loan
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	[2]	1,609,236	1,561,109
Variable rate notes		1,044,598	1,045,182
Total notes payable and unsecured notes		2,361,027
Deferred Finance Costs, Net		14,760	14,703
Amount of debt premium		16,652	19,686
Credit Facility
Notes Payable, Unsecured Notes and Credit Facility
Credit Facility		$ 0	$ 0

[1] Balances at March 31, 2016 and December 31, 2015 exclude $7,310 and $7,601, respectively, of debt discount, and $20,836 and $21,725, respectively, of deferred financing costs, as reflected in unsecured notes, net on the Company’s Condensed Consolidated Balance Sheets.

[2] Balances at March 31, 2016 and December 31, 2015 exclude $16,652 and $19,686, respectively, of debt premium, and $14,760 and $14,703, respectively, of deferred financing costs, as reflected in mortgage notes payable on the Company’s Condensed Consolidated Balance Sheets.