Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Document Fiscal Year Focus			2018
Other expense (income):
Provision for impairment, net of tax			$ 29,443	$ 0
Gain (Loss) on Sale of Properties, Net of Applicable Income Taxes			4,448	4,913
Parent Company [Member]
Revenues:
Minimum rent	$ 204,005	$ 195,393	614,224	532,625
Percentage rent	1,224	1,147	6,292	5,509
Revenue from Contract with Customer, Including Assessed Tax	66,127	59,554	194,900	162,089
Property Management Fee Revenue	6,954	6,047	20,999	19,353
Total revenues	278,310	262,141	836,415	719,576
Operating expenses:
Depreciation and amortization	89,183	91,474	266,812	243,757
Operating and maintenance	40,557	38,020	124,924	103,888
General and administrative	17,564	15,199	51,947	49,618
Real estate taxes	35,129	29,315	97,096	79,636
Other operating expenses (note 2)	2,045	3,195	6,476	81,621
Total operating expenses	184,478	177,203	547,255	558,520
Other expense (income):
Interest expense, net	36,618	34,679	111,477	97,285
Provision for impairment, net of tax	855	0	29,443	0
Gain (Loss) on Extinguishment of Debt	0	0	11,172	12,404
Marketable Securities, Gain (Loss), Excluding Other-than-temporary Impairment Loss	(923)	(971)	(1,524)	(2,955)
Nonoperating Income (Expense)	36,550	33,708	150,568	106,734
Income from operations before equity in income of investments in real estate partnerships	57,282	51,230	138,592	54,322
Equity in income of investments in real estate partnerships	10,024	12,221	29,548	33,804
Income from operations	67,306	63,451	168,140	88,126
Gain (Loss) on Sale of Properties, Net of Applicable Income Taxes	3,228	131	4,448	4,913
Net income	70,534	63,582	172,588	93,039
Noncontrolling interests:
Noncontrolling Interest in Net Income (Loss) Operating Partnerships, Redeemable	147	132	358	217
Limited partners’ interests in consolidated partnerships	(665)	(637)	(2,008)	(1,884)
Income attributable to noncontrolling interests	(812)	(769)	(2,366)	(2,101)
Net income attributable to the Company	69,722	62,813	170,222	90,938
Preferred stock dividends and issuance costs	0	(3,147)	0	(16,128)
Net Income (Loss) Available to Common Stockholders, Basic	$ 69,722	$ 59,666	$ 170,222	$ 74,810
Income per common share/unit - basic:
Continuing operations (in dollars per share)	$ 0.41	$ 0.35	$ 1.00	$ 0.48
Income per common share/unit - diluted:
Continuing operations (in dollars per share)	$ 0.41	$ 0.35	$ 1.00	$ 0.48
Partnership Interest [Member]
Revenues:
Minimum rent	$ 204,005	$ 195,393	$ 614,224	$ 532,625
Percentage rent	1,224	1,147	6,292	5,509
Revenue from Contract with Customer, Including Assessed Tax	66,127	59,554	194,900	162,089
Property Management Fee Revenue	6,954	6,047	20,999	19,353
Total revenues	278,310	262,141	836,415	719,576
Operating expenses:
Depreciation and amortization	89,183	91,474	266,812	243,757
Operating and maintenance	40,557	38,020	124,924	103,888
General and administrative	17,564	15,199	51,947	49,618
Real estate taxes	35,129	29,315	97,096	79,636
Other operating expenses (note 2)	2,045	3,195	6,476	81,621
Total operating expenses	184,478	177,203	547,255	558,520
Other expense (income):
Interest expense, net	36,618	34,679	111,477	97,285
Provision for impairment, net of tax	855	0	29,443	0
Gain (Loss) on Extinguishment of Debt	0	0	11,172	12,404
Marketable Securities, Gain (Loss), Excluding Other-than-temporary Impairment Loss	(923)	(971)	(1,524)	(2,955)
Nonoperating Income (Expense)	36,550	33,708	150,568	106,734
Income from operations before equity in income of investments in real estate partnerships	57,282	51,230	138,592	54,322
Equity in income of investments in real estate partnerships	10,024	12,221	29,548	33,804
Income from operations	67,306	63,451	168,140	88,126
Gain (Loss) on Sale of Properties, Net of Applicable Income Taxes	3,228	131	4,448	4,913
Net income	70,534	63,582	172,588	93,039
Noncontrolling interests:
Limited partners’ interests in consolidated partnerships	(665)	(637)	(2,008)	(1,884)
Income attributable to noncontrolling interests	(665)	(637)	(2,008)	(1,884)
Net income attributable to the Company	69,869	62,945	170,580	91,155
Distributions Paid To Preferred Unit Holders	0	(3,147)	0	(16,128)
Net income attributable to common unit holders	$ 69,869	$ 59,798	$ 170,580	$ 75,027
Income per common share/unit - basic:
Continuing operations (in dollars per share)	$ 0.41	$ 0.35	$ 1.00	$ 0.48
Income per common share/unit - diluted:
Continuing operations (in dollars per share)	$ 0.41	$ 0.35	$ 1.00	$ 0.48