Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities:
Net income	$ 177,716	$ 211,558
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	381,938	372,210
Loss (gain) on sale of depreciable real estate assets	7	(987)
Gain on sale of non-depreciable real estate assets	(995)	(9,260)
Loss (gain) on embedded derivative in preferred shares	14,603	(19,592)
Stock compensation expense	12,532	11,550
Amortization of debt issuance costs, discounts and premiums	3,595	4,706
Net change in operating accounts and other operating activities	54,489	51,353
Net cash provided by operating activities	643,885	621,538
Cash flows from investing activities:
Purchases of real estate and other assets	(5,004)	(22,860)
Capital improvements, development and other	(288,183)	(219,670)
Distributions from real estate joint ventures	207	365
Contributions to affiliates	(3,450)	(4,500)
Proceeds from disposition of real estate assets	3,278	15,984
Net cash used in investing activities	(293,152)	(230,681)
Cash flows from financing activities:
Proceeds from revolving credit facility	245,000	565,000
Repayments of revolving credit facility	(245,000)	(1,105,000)
Net (repayments of) proceeds from commercial paper	(35,000)	200,000
Proceeds from notes payable	447,593	760,003
Principal payments on notes payable	(440,222)	(468,635)
Payment of deferred financing costs	(4,196)	(11,530)
Distributions to noncontrolling interests	(11,993)	(11,813)
Distributions paid on common shares/units	(342,983)	(328,239)
Distributions paid on preferred shares/units	(2,766)	(2,766)
Net change in other financing activities	(4,118)	3,132
Net cash used in financing activities	(393,685)	(399,848)
Net decrease in cash, cash equivalents and restricted cash	(42,952)	(8,991)
Cash, cash equivalents and restricted cash, beginning of period	70,541	51,673
Cash, cash equivalents and restricted cash, end of period	27,589	42,682
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	18,407	25,826
Restricted cash	9,182	16,856
Cash, cash equivalents and restricted cash, end of period	27,589	42,682
Supplemental disclosure of cash flow information:
Interest paid	109,527	108,249
Income taxes paid	2,534	2,509
Supplemental disclosure of noncash investing and financing activities:
Conversion of OP Units to shares of common stock	471	1,993
Accrued construction in progress	41,443	14,652
Interest capitalized	4,783	1,847
Limited Partner [Member]
Cash flows from operating activities:
Net income	177,716	211,558
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	381,938	372,210
Loss (gain) on sale of depreciable real estate assets	7	(987)
Gain on sale of non-depreciable real estate assets	(995)	(9,260)
Loss (gain) on embedded derivative in preferred shares	14,603	(19,592)
Stock compensation expense	12,532	11,550
Amortization of debt issuance costs, discounts and premiums	3,595	4,706
Net change in operating accounts and other operating activities	54,489	51,353
Net cash provided by operating activities	643,885	621,538
Cash flows from investing activities:
Purchases of real estate and other assets	(5,004)	(22,860)
Capital improvements, development and other	(288,183)	(219,670)
Distributions from real estate joint ventures	207	365
Contributions to affiliates	(3,450)	(4,500)
Proceeds from disposition of real estate assets	3,278	15,984
Net cash used in investing activities	(293,152)	(230,681)
Cash flows from financing activities:
Proceeds from revolving credit facility	245,000	565,000
Repayments of revolving credit facility	(245,000)	(1,105,000)
Net (repayments of) proceeds from commercial paper	(35,000)	200,000
Proceeds from notes payable	447,593	760,003
Principal payments on notes payable	(440,222)	(468,635)
Payment of deferred financing costs	(4,196)	(11,530)
Distributions paid on common shares/units	(354,976)	(340,052)
Distributions paid on preferred shares/units	(2,766)	(2,766)
Net change in other financing activities	(4,118)	3,132
Net cash used in financing activities	(393,685)	(399,848)
Net decrease in cash, cash equivalents and restricted cash	(42,952)	(8,991)
Cash, cash equivalents and restricted cash, beginning of period	70,541	51,673
Cash, cash equivalents and restricted cash, end of period	27,589	42,682
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	18,407	25,826
Restricted cash	9,182	16,856
Cash, cash equivalents and restricted cash, end of period	27,589	42,682
Supplemental disclosure of cash flow information:
Interest paid	109,527	108,249
Income taxes paid	2,534	2,509
Supplemental disclosure of noncash investing and financing activities:
Accrued construction in progress	41,443	14,652
Interest capitalized	$ 4,783	$ 1,847