Indebtedness (Tables)

12 Months Ended

Dec. 31, 2012

Debt Disclosure [Abstract]

Schedule of Long-term Debt Instruments

Indebtedness at December 31, 2012 and 2011 consists of the following (in thousands):

	Maturity Date	Weighted Average Interest Rate		Weighted Average Interest Rate
		2012		2011		2012		2011
Fixed rate secured debt	2013 to 2027	6.19	%	6.25	%	$	1,149,541	$	1,167,188
Variable rate secured debt	2014 to 2025	2.01	%	0.21	%	18,412		6,045
Fixed rate unsecured debt	2013 to 2028	6.17	%	6.56	%	2,993,217		2,616,063
Unsecured lines of credit	2015	1.47	%	1.14	%	285,000		20,293
						$	4,446,170	$	3,809,589

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

As all of our fair value debt disclosures relied primarily on Level 3 inputs, the following table summarizes the book value and changes in the fair value of our debt for the year ended December 31, 2012 (in thousands): 

	Book Value at		Book Value at		Fair Value at		Issuances					Adjustments			Fair Value at
	December 31, 2011		December 31, 2012		December 31, 2011		and Assumptions		Payoffs			to Fair Value			December 31, 2012
Fixed rate secured debt	$	1,167,188	$	1,149,541	$	1,256,331	$	100,826	$	(116,319	)	$	10,639		$	1,251,477
Variable rate secured debt	6,045		18,412		6,045		13,336		(968		)	(27		)	18,386
Unsecured notes	2,616,063		2,993,217		2,834,610		600,000		(222,846		)	124,622			3,336,386
Unsecured lines of credit	20,293		285,000		20,244		285,000		(20,293		)	681			285,632
Total	$	3,809,589	$	4,446,170	$	4,117,230	$	999,162	$	(360,426	)	$	135,915		$	4,891,881

Unsecured Lines of Credit

Our unsecured line of credit as of December 31, 2012 is described as follows (in thousands):

				Outstanding Balance at
Description	Maximum Capacity		Maturity Date	December 31, 2012
Unsecured Line of Credit – Partnership	$	850,000	December 2015	$	285,000

Schedule of Maturities of Long-term Debt

At December 31, 2012, the scheduled amortization and maturities of all indebtedness, excluding fair value and other accounting adjustments, for the next five years and thereafter were as follows (in thousands):

Year	Amount
2013	$	547,732
2014	331,563
2015	679,945
2016	544,840
2017	566,611
Thereafter	1,768,944
	$	4,439,635