Consolidated Balance Sheets (Unaudited) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012		Dec. 31, 2011
REAL ESTATE ASSETS:
Land and improvements (Note 2)	$ 576,433		$ 537,574
Buildings and improvements	2,970,967		2,830,310
Undeveloped land and construction in progress	446,237		430,806
Total real estate held for investment	3,993,637		3,798,690
Accumulated depreciation and amortization	(770,688)		(742,503)
Total real estate assets held for investment, net	3,222,949		3,056,187
REAL ESTATE ASSETS AND OTHER ASSETS HELD FOR SALE, NET (Note 14)	0		84,156
CASH AND CASH EQUIVALENTS	374,368		4,777
RESTRICTED CASH (Note 14)	43,140		358
MARKETABLE SECURITIES (Note 12)	6,459		5,691
CURRENT RECEIVABLES, NET (Note 4)	6,990		8,395
DEFERRED RENT RECEIVABLES, NET (Note 4)	106,309		101,142
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET (Notes 2 and 3)	158,132	[1]	155,522
DEFERRED FINANCING COSTS, NET	19,060		18,368
PREPAID EXPENSES AND OTHER ASSETS, NET (Note 11)	21,934		12,199
TOTAL ASSETS	3,959,341		3,446,795
LIABILITIES:
Secured debt, net (Notes 5 and 12)	350,219		351,825
Exchangeable senior notes, net (Notes 5, 12 and 17)	308,689		306,892
Unsecured debt, net (Notes 5 and 12)	1,130,651		980,569
Unsecured line of credit (Notes 5, 12 and 17)	0		182,000
Accounts payable, accrued expenses and other liabilities	92,574		81,713
Accrued distributions (Note 17)	26,622		22,692
Deferred revenue and acquisition-related intangible liabilities, net (Notes 2 and 3)	90,206		79,781
Rents received in advance and tenant security deposits	30,392		26,917
Liabilities and deferred revenue of real estate assets held for sale (Note 14)	0		13,286
7.80% Series E and 7.50% Series F Cumulative Redeemable Preferred stock, called for redemption (Note 7)	126,500		0
Total liabilities	2,155,853		2,045,675
COMMITMENTS AND CONTINGENCIES (Note 11)
NONCONTROLLING INTEREST (Note 6):
7.45% Series A Cumulative Redeemable Preferred units of the Operating Partnership	73,638		73,638
Preferred stock, $.01 par value, 30,000,000 shares authorized:
Common stock, $.01 par value, 150,000,000 shares authorized, 68,349,843 and 58,819,717 shares issued and outstanding, respectively	683		588
Additional paid-in capital	1,827,676		1,448,997
Distributions in excess of earnings	(234,199)		(277,450)
Total stockholders' equity	1,690,315		1,293,717
Noncontrolling interest :
Common units of the Operating Partnership ( Note 6 )	39,535		33,765
Total equity	1,729,850		1,327,482
TOTAL LIABILITIES, NONCONTROLLING INTEREST AND EQUITY	3,959,341		3,446,795
Series A Cumulative Redeemable Preferred Stock
Preferred stock, $.01 par value, 30,000,000 shares authorized:
Cumulative Redeemable Preferred stock	0		0
Series E Cumulative Redeemable Preferred Stock
Preferred stock, $.01 par value, 30,000,000 shares authorized:
Cumulative Redeemable Preferred stock	0		38,425
Series F Cumulative Redeemable Preferred Stock
Preferred stock, $.01 par value, 30,000,000 shares authorized:
Cumulative Redeemable Preferred stock	0		83,157
Series G Cumulative Redeemable Preferred Stock
Preferred stock, $.01 par value, 30,000,000 shares authorized:
Cumulative Redeemable Preferred stock	$ 96,155		$ 0

[1] Balances and accumulated amortization amounts at March 31, 2012 reflect the write-off of the following fully amortized amounts at January 1, 2012: deferred leasing costs (approximately $9.5 million), above-market leases (approximately $1.6 million), in-place leases (approximately $3.7 million), and below-market leases (approximately $1.0 million).