Indebtedness (Tables)

12 Months Ended

Dec. 31, 2011

Extinguishment of Debt [Line Items]

Information regarding indebtedness

	Outstanding Balance at						Interest Rate at December 31, 2011	Effective Interest Rate at Issuance	Maturity Date
	December 31, 2011			December 31, 2010
Mortgage and Other Loans Payable, Net*	$	690,256		$	486,055		4.45% – 9.25%	4.45% – 9.25%	January 2013 – October 2021
Unamortized Premiums*		(305	)		(358	)
Mortgage and Other Loans Payable, Gross*	$	689,951		$	485,697
Senior Unsecured Notes, Net
2016 Notes	$	159,455		$	159,899		5.750%	5.91%	01/15/16
2017 Notes		59,600			87,195		7.500%	7.52%	12/01/17
2027 Notes		6,065			13,559		7.150%	7.11%	05/15/27
2028 Notes		124,894			189,869		7.600%	8.13%	07/15/28
2012 Notes		61,817			61,774		6.875%	6.85%	04/15/12
2032 Notes		34,683			34,667		7.750%	7.87%	04/15/32
2014 Notes		86,997			86,792		6.420%	6.54%	06/01/14
2011 Exchangeable Notes		—			128,137		N/A	N/A	09/15/11
2017 II Notes		106,716			117,637		5.950%	6.37%	05/15/17
Subtotal	$	640,227		$	879,529
Unamortized Discounts		4,625			6,980
Senior Unsecured Notes, Gross	$	644,852		$	886,509
Unsecured Credit Facility	$	149,000		$	376,184		2.385%	2.385%	12/12/14

* Excludes $1,008 of Mortgage Loan Payable on Real Estate Held for Sale which is net of $48 of unamortized premiums as of December 31, 2010.

Mortgage Loans Obtained [Table Text Block]

Mortgage Financing	Loan Principal		Interest Rate			Origination/Assumption Date	Maturity Date	Amortization Period		Number of Industrial Properties Collateralizing Mortgage		GLA (In millions)		Property Carrying Value at December 31, 2011
I - VIII	$	178,300		4.45	%	May 2, 2011	June 2018		30-year		32		5.9	$	206,291
IX		24,417		5.579	%	May 26, 2011	February 2016		30-year		1		0.7		28,991
X-XX		77,600		4.85	%	September 23, 2011	October 2021		30-year		24		2.3		84,403
	$	280,317												$	319,685

Summary of the stated maturities and scheduled principal payments

	Amount
2012	$	74,518
2013		13,164
2014		305,063
2015		62,088
2016		293,467
Thereafter		735,503
Total	$	1,483,803

Summary of fair value indebtedness

	December 31, 2011				December 31, 2010
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Mortgage and Other Loans Payable, including mortgages Held for Sale	$	690,256	$	743,419	$	487,063	$	548,696
Senior Unsecured Debt		640,227		630,622		879,529		851,771
Unsecured Credit Facility		149,000		149,000		376,184		376,184
Total	$	1,479,483	$	1,523,041	$	1,742,776	$	1,776,651

Mortgages [Member]

Extinguishment of Debt [Line Items]

Early extinguishment of mortgage loans and senior unsecured notes

Loan Principal Paid Off	Interest Rate			Payoff Date	Maturity Date	(Loss) Gain on Retirement  of Debt
$14,520		6.75	%	February 10, 2011	September 2012	$	(213	)
18,662		7.50	%	March 9, 2011	December 2014		(813	)
27,389		7.50	%	April 1, 2011	October 2014		(1,104	)
2,091		7.54	%	November 30, 2011	January 2012		2
$62,662						$	(2,128	)

Senior unsecured notes [Member]

Extinguishment of Debt [Line Items]

Early extinguishment of mortgage loans and senior unsecured notes

	Principal Amount Repurchased				Purchase Price
	For the Year Ended December 31, 2011		For the Year Ended December 31, 2010		For the Year Ended December 31, 2011		For the Year Ended December 31, 2010
2011 Notes	$	—	$	143,498	$	—	$	147,723
2011 Exchangeable Notes		—		18,000		—		17,936
2012 Notes		—		82,236		—		82,235
2014 Notes		1,144		21,062		1,143		17,964
2016 Notes		500		—		475		—
2017 Notes		27,619		—		27,506		—
2017 II Notes		10,969		—		10,182		—
2027 Notes		7,500		—		7,500		—
2028 Notes		65,025		—		63,861		—
	$	112,757	$	264,796	$	110,667	$	265,858