Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Lease Income	$ 277,303
Document Fiscal Year Focus	2019
Other expense (income):
Provision for impairment, net of tax	$ 1,672	$ 374
Gain (Loss) on Sale of Properties, Net of Applicable Income Taxes	(16,490)	(96)
Parent Company [Member]
Lease Income	277,303	267,510
Revenues:
Other Operating Income	1,982	2,025
Property Management Fee Revenue	6,972	7,158
Total revenues	286,257	276,693
Operating expenses:
Depreciation and amortization	97,194	88,525
Operating and maintenance	40,638	42,516
General and administrative	21,300	17,606
Real estate taxes	34,155	30,425
Other operating expenses	1,134	1,632
Total operating expenses	194,421	180,704
Other expense (income):
Interest expense, net	37,752	36,785
Provision for impairment, net of tax	1,672	16,054
Gain (Loss) on Extinguishment of Debt	10,591	162
Marketable Securities, Gain (Loss), Excluding Other-than-temporary Impairment Loss	(2,354)	(32)
Nonoperating Income (Expense)	31,171	52,873
Income from operations before equity in income of investments in real estate partnerships	60,665	43,116
Equity in income of investments in real estate partnerships	30,828	10,349
Gain (Loss) on Sale of Properties, Net of Applicable Income Taxes	(16,490)	(96)
Net income	91,493	53,465
Noncontrolling interests:
Noncontrolling Interest in Net Income (Loss) Operating Partnerships, Redeemable	190	111
Limited partners’ interests in consolidated partnerships	(857)	(694)
Income attributable to noncontrolling interests	(1,047)	(805)
Net income attributable to the Company	90,446	52,660
Net Income (Loss) Available to Common Stockholders, Basic	$ 90,446	$ 52,660
Income per common share/unit - basic:
Continuing operations (in dollars per share)	$ 0.54	$ 0.31
Income per common share/unit - diluted:
Continuing operations (in dollars per share)	$ 0.54	$ 0.31
Partnership Interest [Member]
Lease Income	$ 277,303	$ 267,510
Revenues:
Other Operating Income	1,982	2,025
Property Management Fee Revenue	6,972	7,158
Total revenues	286,257	276,693
Operating expenses:
Depreciation and amortization	97,194	88,525
Operating and maintenance	40,638	42,516
General and administrative	21,300	17,606
Real estate taxes	34,155	30,425
Other operating expenses	1,134	1,632
Total operating expenses	194,421	180,704
Other expense (income):
Interest expense, net	37,752	36,785
Provision for impairment, net of tax	1,672	16,054
Gain (Loss) on Extinguishment of Debt	10,591	162
Marketable Securities, Gain (Loss), Excluding Other-than-temporary Impairment Loss	(2,354)	(32)
Nonoperating Income (Expense)	31,171	52,873
Income from operations before equity in income of investments in real estate partnerships	60,665	43,116
Equity in income of investments in real estate partnerships	30,828	10,349
Gain (Loss) on Sale of Properties, Net of Applicable Income Taxes	(16,490)	(96)
Net income	91,493	53,465
Noncontrolling interests:
Limited partners’ interests in consolidated partnerships	(857)	(694)
Income attributable to noncontrolling interests	(857)	(694)
Net income attributable to common unit holders	$ 90,636	$ 52,771
Income per common share/unit - basic:
Continuing operations (in dollars per share)	$ 0.54	$ 0.31
Income per common share/unit - diluted:
Continuing operations (in dollars per share)	$ 0.54	$ 0.31