Indebtedness (Tables)

3 Months Ended

Mar. 31, 2012

Debt Disclosure [Abstract]

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

	Book Value at 12/31/11		Book Value at 3/31/12		Fair Value at 12/31/11		Issuances and Assumptions		Payoffs			Adjustments to Fair Value			Fair Value at 3/31/12
Fixed rate secured debt	$	1,167,188	$	1,174,920	$	1,256,331	$	18,741	$	(11,009	)	$	(840	)	$	1,263,223
Variable rate secured debt	6,045		6,045		6,045		—		—			—			6,045
Unsecured notes	2,616,063		2,615,612		2,834,610		—		(451		)	59,227			2,893,386
Unsecured lines of credit	20,293		20,293		20,244		—		—			4			20,248
Total	$	3,809,589	$	3,816,870	$	4,117,230	$	18,741	$	(11,460	)	$	58,391		$	4,182,902

Unsecured Lines of Credit

Description	Maximum Capacity		Maturity Date	Outstanding Balance at March 31, 2012
Unsecured Line of Credit - DRLP	$	850,000	December 2015	$	—
Unsecured Line of Credit - Consolidated Subsidiary	$	30,000	July 2012	$	20,293