Fair Value of Derivatives and Financial Instruments (Tables)

6 Months Ended

Jun. 30, 2011

Fair Value of Derivatives and Financial Instruments [Abstract]

Estimated fair values of financial instruments either recorded or disclosed on a recurring basis

			Fair Value at June 30, 2011 Using
			Quoted Prices in
			Active Markets		Significant
			for Identical		Other		Significant
			Assets or		Observable		Unobservable
			Liabilities		Inputs		Inputs
	June 30, 2011		(Level 1)		(Level 2)		(Level 3)
Description:
Derivatives- Interest rate contracts (c)	$	148	$	—	$	148	$	—
Total assets	$	148	$	—	$	148	$	—
Derivatives- Interest rate contracts (c)	$	9,979	$	—	$	9,979	$	—
Contingent purchase consideration (d)		5,402		—		—		5,402
Secured debt instruments- fixed rate: (a)
Mortgage notes payable		597,645		—		—		597,645
Fannie Mae credit facilities		931,648		—		—		931,648
Secured debt instruments- variable rate: (a)
Mortgage notes payable		177,201		—		—		177,201
Tax-exempt secured notes payable		94,700		—		—		94,700
Fannie Mae credit facilities		260,451		—		—		260,451
Unsecured debt instruments: (b)
Commercial bank		5,000		—		—		5,000
Senior Unsecured Notes		1,778,649		97,099		—		1,681,550
Total liabilities	$	3,860,675	$	97,099	$	9,979	$	3,753,597

			Fair Value at December 31, 2010 Using
			Quoted Prices in
			Active Markets		Significant
			for Identical		Other		Significant
			Assets or		Observable		Unobservable
			Liabilities		Inputs		Inputs
	December 31, 2010		(Level 1)		(Level 2)		(Level 3)
Description:
Available-for-sale equity securities	$	3,866	$	3,866	$	—	$	—
Derivatives- Interest rate contracts (c)		514		—		514		—
Total assets	$	4,380	$	3,866	$	514	$	—
Derivatives- Interest rate contracts (c)	$	6,597	$	—	$	6,597	$	—
Contingent purchase consideration (d)		5,402		—		—		5,402
Secured debt instruments- fixed rate: (a)
Mortgage notes payable		306,515		—		—		306,515
Tax-exempt secured notes payable		13,885		—		—		13,885
Fannie Mae credit facilities		927,413		—		—		927,413
Secured debt instruments- variable rate: (a)
Mortgage notes payable		405,641		—		—		405,641
Tax-exempt secured notes payable		94,700		—		—		94,700
Fannie Mae credit facilities		260,450		—		—		260,450
Unsecured debt instruments: (b)
Commercial bank		31,750		—		—		31,750
Senior Unsecured Notes		1,625,492		264,849		—		1,360,643
Total liabilities	$	3,677,845	$	264,849	$	6,597	$	3,406,399

(a)	See Note 6, “Secured Debt”
(b)	See Note 7, “Unsecured Debt”
(c)	See Note 11, “Derivatives and Hedging Activity”
(d)	In the first quarter of 2010, the Company accrued a liability of $6 million related to a contingent purchase consideration on one of its properties. The contingent consideration was determined based on the fair market value of the related asset which is estimated using Level 3 inputs utilized in a third party appraisal. During the year ended December 31, 2010, the Company paid approximately $635,000 of the liability, and the outstanding balance is due January 2012.