Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
PROPERTIES:
Operating properties, net of accumulated depreciation of $283,119 and $235,707 in 2014 and 2013, respectively	$ 1,817,439	$ 1,828,437
Projects under development	56,760	21,681
Land	26,790	35,053
Total properties	1,900,989	1,885,171
Operating properties and related assets held for sale, net of accumulated depreciation of $12,001 and $21,444 in 2014 and 2013, respectively	11,396	24,554
Cash and cash equivalents	6,257	975
Restricted cash	3,912	2,810
Notes and accounts receivable, net of allowance for doubtful accounts of $1,335 and $1,827 in 2014 and 2013, respectively	10,733	11,778
Deferred rents receivable	51,555	39,969
Investment in unconsolidated joint ventures	111,164	107,082
Intangible assets, net of accumulated amortization of $60,591 and $37,544 in 2014 and 2013, respectively	147,721	170,973
Intangible assets, net of accumulated amortization of $60,591 and $37,544 in 2014 and 2013, respectively	35,773	29,894
Other assets	2,279,500	2,273,206
LIABILITIES AND EQUITY
Notes payable	665,852	630,094
Accounts payable and accrued expenses	72,577	76,668
Deferred income	23,681	25,754
Intangible liabilities, net of accumulated amortization of $11,993 and $6,323 in 2014 and 2013, respectively	60,806	66,476
Other liabilities	15,704	15,242
Total liabilities	838,620	814,234
STOCKHOLDERS' INVESTMENT:
Preferred stock, 7.50% Series B cumulative redeemable preferred stock, $1 par value, $25 liquidation preference, 20,000,000 shares authorized, -0- and 3,791,000 shares issued and outstanding in 2014 and 2013, respectively	0	94,775
Common stock, $1 par value, 350,000,000 shares authorized, 202,043,854 and 193,236,454 shares issued in 2014 and 2013, respectively	202,044	193,236
Additional paid-in capital	1,514,959	1,420,951
Treasury stock at cost, 3,570,082 shares in 2014 and 2013	(86,840)	(86,840)
Distributions in excess of cumulative net income	(190,857)	(164,721)
TOTAL STOCKHOLDERS’ INVESTMENT	1,439,306	1,457,401
Nonredeemable noncontrolling interests	1,574	1,571
Total equity	1,440,880	1,458,972
Total liabilities and equity	$ 2,279,500	$ 2,273,206