Indebtedness (Tables)

6 Months Ended

Jun. 30, 2014

Debt Disclosure [Abstract]

Fair Value, Liabilities Measured on a Recurring Basis, Disclosure Only

	Book Value at 12/31/13		Book Value at 6/30/14		Fair Value at 12/31/13		Payments/Payoffs			Adjustments to Fair Value			Fair Value at 6/30/14
Fixed rate secured debt	$	1,081,035	$	1,004,327	$	1,145,717	$	(74,144	)	$	26,987		$	1,098,560
Variable rate secured debt	19,089		4,335		19,089		(14,754		)	—			4,335
Unsecured debt	3,066,252		3,065,223		3,250,518		(1,029		)	83,352			3,332,841
Unsecured line of credit	88,000		60,000		88,383		(28,000		)	(141		)	60,242
Total	$	4,254,376	$	4,133,885	$	4,503,707	$	(117,927	)	$	110,198		$	4,495,978

Unsecured Line of Credit

Description	Maximum Capacity		Maturity Date	Outstanding Balance at June 30, 2014
Unsecured Line of Credit - Partnership	$	850,000	December 2015	$	60,000