Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Other expense (income):
Provision for impairment	$ 0	$ 0	$ 1,666	$ 0
Discontinued operations, net:
Gain (Loss) on Sale of Properties, Net of Applicable Income Taxes	9,580	27,755	22,997	34,215
Net income			105,334	129,004
Parent Company [Member]
Noncontrolling Interest in Net Income (Loss) Operating Partnerships, Redeemable	16	94	165	204
Revenues:
Minimum rent	111,886	105,071	329,506	308,766
Percentage rent	495	486	2,651	2,593
Recoveries from tenants and other income	34,532	30,725	103,894	94,205
Management Fees Revenue	5,855	5,786	18,759	18,032
Total revenues	152,768	142,068	454,810	423,596
Operating expenses:
Depreciation and amortization	40,705	37,032	119,721	109,249
Operating and maintenance	23,373	19,761	69,767	61,119
General and administrative	16,046	14,750	48,695	46,227
Real estate taxes	17,058	16,044	49,697	46,842
Other operating expenses	1,046	1,880	5,795	4,825
Total operating expenses	98,228	89,467	293,675	268,262
Other expense (income):
Interest expense, net	21,945	25,099	70,489	78,407
Provision for impairment	0	0	1,666	0
Early extinguishment of debt	(13,943)	0	(13,943)	61
Marketable Securities, Gain (Loss), Excluding Other than Temporary Impairments	821	(1,190)	1,268	(190)
Gain (Loss) on Derivative Instruments, Net, Pretax	40,586	0	40,586	0
Nonoperating Income (Expense)	75,653	26,289	125,416	78,536
Income (loss) from operations before equity in income of investments in real estate partnerships	(21,113)	26,312	35,719	76,798
Equity in income of investments in real estate partnerships	22,647	5,667	46,618	17,991
Income from operations	1,534	31,979	82,337	94,789
Discontinued operations, net:
Gain (Loss) on Sale of Properties, Net of Applicable Income Taxes	9,580	27,755	22,997	34,215
Net income	11,114	59,734	105,334	129,004
Noncontrolling interests:
Limited partners’ interests in consolidated partnerships	(527)	(643)	(1,380)	(1,619)
Income attributable to noncontrolling interests	(543)	(737)	(1,545)	(1,823)
Net income attributable to the Company	10,571	58,997	103,789	127,181
Preferred stock dividends	(5,266)	(5,266)	(15,797)	(15,797)
Net Income (Loss) Available to Common Stockholders, Basic	$ 5,305	$ 53,731	$ 87,992	$ 111,384
Income per common share/unit - basic:
Continuing operations (in dollars per share)	$ 0.05	$ 0.57	$ 0.88	$ 1.18
Income per common share/unit - diluted:
Continuing operations (in dollars per share)	$ 0.05	$ 0.57	$ 0.88	$ 1.18
Partnership Interest [Member]
Revenues:
Minimum rent	$ 111,886	$ 105,071	$ 329,506	$ 308,766
Percentage rent	495	486	2,651	2,593
Recoveries from tenants and other income	34,532	30,725	103,894	94,205
Management Fees Revenue	5,855	5,786	18,759	18,032
Total revenues	152,768	142,068	454,810	423,596
Operating expenses:
Depreciation and amortization	40,705	37,032	119,721	109,249
Operating and maintenance	23,373	19,761	69,767	61,119
General and administrative	16,046	14,750	48,695	46,227
Real estate taxes	17,058	16,044	49,697	46,842
Other operating expenses	1,046	1,880	5,795	4,825
Total operating expenses	98,228	89,467	293,675	268,262
Other expense (income):
Interest expense, net	21,945	25,099	70,489	78,407
Provision for impairment	0	0	1,666	0
Early extinguishment of debt	(13,943)	0	(13,943)	61
Marketable Securities, Gain (Loss), Excluding Other than Temporary Impairments	821	(1,190)	1,268	(190)
Gain (Loss) on Derivative Instruments, Net, Pretax	40,586	0	40,586	0
Nonoperating Income (Expense)	75,653	26,289	125,416	78,536
Income (loss) from operations before equity in income of investments in real estate partnerships	(21,113)	26,312	35,719	76,798
Equity in income of investments in real estate partnerships	22,647	5,667	46,618	17,991
Income from operations	1,534	31,979	82,337	94,789
Discontinued operations, net:
Gain (Loss) on Sale of Properties, Net of Applicable Income Taxes	9,580	27,755	22,997	34,215
Net income	11,114	59,734	105,334	129,004
Noncontrolling interests:
Limited partners’ interests in consolidated partnerships	(527)	(643)	(1,380)	(1,619)
Income attributable to noncontrolling interests	(527)	(643)	(1,380)	(1,619)
Net income attributable to the Company	10,587	59,091	103,954	127,385
Distributions Paid To Preferred Unit Holders	5,266	5,266	15,797	15,797
Net income attributable to common unit holders	$ 5,321	$ 53,825	$ 88,157	$ 111,588
Income per common share/unit - basic:
Continuing operations (in dollars per share)	$ 0.05	$ 0.57	$ 0.88	$ 1.18
Income per common share/unit - diluted:
Continuing operations (in dollars per share)	$ 0.05	$ 0.57	$ 0.88	$ 1.18