Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Document Fiscal Year Focus	2017
Revenues:
Recoveries from tenants and other income	$ 14,825	$ 9,221
Other expense (income) [Abstract]
Provision for impairment	0	1,700	$ 0
Equity in income of investments in real estate partnerships (note 4)	43,341	56,518	22,508
Federal Income Tax Expense (Benefit), Continuing Operations	(9,647)	(153)	(1,604)
Gain (Loss) on Sale of Properties, Net of Applicable Income Taxes	27,432	47,321	35,606
Parent Company [Member]
Revenues:
Minimum rent	728,078	444,305	415,155
Percentage rent	6,635	4,128	3,750
Recoveries from tenants and other income	223,455	140,611	125,295
Management Fees Revenue	26,158	25,327	25,563
Total revenues	984,326	614,371	569,763
Operating expenses:
Depreciation and amortization	334,201	162,327	146,829
Operating and maintenance	143,990	95,022	82,978
General and administrative	67,624	65,327	65,600
Real estate taxes	109,723	66,395	61,855
Other operating expenses	89,225	14,081	7,836
Total operating expenses	744,763	403,152	365,098
Other expense (income) [Abstract]
Interest Expense	132,629	90,712	102,622
Provision for impairment	0	4,200	0
Early extinguishment of debt	12,449	14,240	8,239
Net investment income, including unrealized (gains) losses of ($1,136), ($773), and $1,734 in 2017, 2016, and 2015, respectively (note 12)	3,985	1,672	625
Gain (Loss) on Derivative Instruments, Net, Pretax	0	40,586	0
Nonoperating Income (Expense)	(141,093)	(148,066)	(110,236)
Income from operations before equity in income of investments in real estate partnerships and income taxes	98,470	63,153	94,429
Equity in income of investments in real estate partnerships (note 4)	43,341	56,518	22,508
Federal Income Tax Expense (Benefit), Continuing Operations	(9,737)	0	0
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	151,548	119,671	116,937
Gain (Loss) on Sale of Properties, Net of Applicable Income Taxes	27,432	47,321	35,606
Net income	178,980	166,992	152,543
Noncontrolling interests:
Noncontrolling Interest in Net Income (Loss) Operating Partnerships, Nonredeemable	(388)	(257)	(240)
Noncontrolling Interest in Net Income (Loss) Limited Partnerships, Nonredeemable	(2,515)	(1,813)	(2,247)
Income attributable to noncontrolling interests	(2,903)	(2,070)	(2,487)
Net income attributable to the Company	176,077	164,922	150,056
Preferred stock dividends and issuance costs	(16,128)	(21,062)	(21,062)
Net Income (Loss) Available to Common Stockholders, Basic	$ 159,949	$ 143,860	$ 128,994
Continuing operations (in dollars per share)	$ 1.00	$ 1.43	$ 1.37
Continuing operations (in dollars per share)	$ 1.00	$ 1.42	$ 1.36
Partnership Interest [Member]
Revenues:
Minimum rent	$ 728,078	$ 444,305	$ 415,155
Percentage rent	6,635	4,128	3,750
Recoveries from tenants and other income	223,455	140,611	125,295
Management Fees Revenue	26,158	25,327	25,563
Total revenues	984,326	614,371	569,763
Operating expenses:
Depreciation and amortization	334,201	162,327	146,829
Operating and maintenance	143,990	95,022	82,978
General and administrative	67,624	65,327	65,600
Real estate taxes	109,723	66,395	61,855
Other operating expenses	89,225	14,081	7,836
Total operating expenses	744,763	403,152	365,098
Other expense (income) [Abstract]
Interest Expense	132,629	90,712	102,622
Provision for impairment	0	4,200	0
Early extinguishment of debt	12,449	14,240	8,239
Net investment income, including unrealized (gains) losses of ($1,136), ($773), and $1,734 in 2017, 2016, and 2015, respectively (note 12)	3,985	1,672	625
Gain (Loss) on Derivative Instruments, Net, Pretax	0	40,586	0
Nonoperating Income (Expense)	(141,093)	(148,066)	(110,236)
Income from operations before equity in income of investments in real estate partnerships and income taxes	98,470	63,153	94,429
Equity in income of investments in real estate partnerships (note 4)	43,341	56,518	22,508
Federal Income Tax Expense (Benefit), Continuing Operations	(9,737)	0	0
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	151,548	119,671	116,937
Gain (Loss) on Sale of Properties, Net of Applicable Income Taxes	27,432	47,321	35,606
Net income	178,980	166,992	152,543
Noncontrolling interests:
Noncontrolling Interest in Net Income (Loss) Limited Partnerships, Nonredeemable	(2,515)	(1,813)	(2,247)
Income attributable to noncontrolling interests	(2,515)	(1,813)	(2,247)
Net income attributable to the Company	176,465	165,179	150,296
Preferred unit distributions	(16,128)	(21,062)	(21,062)
Net (loss) income attributable to common unit holders	$ 160,337	$ 144,117	$ 129,234
Continuing operations (in dollars per share)	$ 1.00	$ 1.43	$ 1.37
Continuing operations (in dollars per share)	$ 1.00	$ 1.42	$ 1.36