Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
REAL ESTATE ASSETS:
Land and improvements	$ 978,643	$ 875,794
Buildings and improvements	4,501,062	4,091,012
Undeveloped land and construction in progress (Note 2)	1,018,738	1,361,340
Total real estate assets held for investment	6,498,443	6,328,146
Accumulated depreciation and amortization	(1,034,315)	(994,241)
Total real estate assets held for investment, net	5,464,128	5,333,905
REAL ESTATE ASSETS AND OTHER ASSETS HELD FOR SALE, NET	0	117,666
CASH AND CASH EQUIVALENTS	38,645	56,508
RESTRICTED CASH (Notes 1 and 3)	261,600	696
MARKETABLE SECURITIES (Note 12)	13,418	12,882
CURRENT RECEIVABLES, NET (Note 5)	9,540	11,153
DEFERRED RENT RECEIVABLES, NET (Note 5)	199,232	189,704	[1]
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET (Note 4)	186,271	176,683
PREPAID EXPENSES AND OTHER ASSETS, NET (Note 1)	31,276	27,233
TOTAL ASSETS	6,204,110	5,926,430
LIABILITIES:
Secured debt, net (Notes 1, 6 and 12)	378,080	380,835
Unsecured debt, net (Notes 1, 6 and 12)	1,845,313	1,844,634
Unsecured line of credit (Notes 6 and 12)	75,000	0
Accounts payable, accrued expenses and other liabilities	265,863	246,323
Accrued dividends and distributions (Note 17)	35,317	34,992
Deferred revenue and acquisition-related intangible liabilities, net (Note 4)	131,296	128,156
Rents received in advance and tenant security deposits	48,543	49,361
Liabilities of real estate assets held for sale	0	7,543
Total liabilities	$ 2,779,412	$ 2,691,844
COMMITMENTS AND CONTINGENCIES (Note 11)
Preferred stock, $.01 par value, 30,000,000 shares authorized:
Common stock, $.01 par value, 150,000,000 shares authorized, 92,229,464 and 92,258,690 shares issued and outstanding, respectively	$ 922	$ 923
Additional paid-in capital	3,066,994	3,047,894
Retained earnings/(distributions in excess of earnings)	67,981	(70,262)
Total stockholders’ equity	3,328,308	3,170,966
Noncontrolling Interests:
Common units of the Operating Partnership (Note 7)	89,675	57,100
Noncontrolling interest in consolidated subsidiary (Note 1)	6,715	6,520
Total noncontrolling interests	96,390	63,620
Total equity	3,424,698	3,234,586
TOTAL LIABILITIES AND EQUITY	6,204,110	5,926,430
6.875% Series G Cumulative Redeemable Preferred stock, $.01 par value, 4,600,000 shares authorized, 4,000,000 shares issued and outstanding ($100,000 liquidation preference) [Member]
Preferred stock, $.01 par value, 30,000,000 shares authorized:
Cumulative Redeemable Preferred stock	96,155	96,155
6.375% Series H Cumulative Redeemable Preferred stock, $.01 par value, 4,000,000 shares authorized, issued and outstanding ($100,000 liquidation preference) [Member]
Preferred stock, $.01 par value, 30,000,000 shares authorized:
Cumulative Redeemable Preferred stock	$ 96,256	$ 96,256

[1] (1)Excludes deferred rent receivables, net related to real estate held for sale at December 31, 2015.