Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net income	$ 48,864	$ 37,952
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	131,820	126,657
Loss on sale of depreciable real estate assets		29
Loss on sale of non-depreciable real estate assets		376
Loss on embedded derivative in preferred shares	15,108	27,638
Stock compensation expense	5,369	5,288
Amortization of debt issuance costs, discounts and premiums	1,344	1,157
Net change in operating accounts and other operating activities	(54,394)	(38,495)
Net cash provided by operating activities	148,111	160,602
Cash flows from investing activities:
Purchases of real estate and other assets		(5,004)
Capital improvements, development and other	(113,511)	(84,610)
Distributions from real estate joint ventures	114
Contributions to affiliates		(900)
Proceeds from disposition of real estate assets	898	525
Net cash used in investing activities	(112,499)	(89,989)
Cash flows from financing activities:
Proceeds from revolving credit facility		130,000
Repayments of revolving credit facility		(30,000)
Net proceeds from (repayments of) commercial paper	213,000	(70,000)
Principal payments on notes payable	(119,154)	(1,740)
Distributions to noncontrolling interests	(4,159)	(4,067)
Distributions paid on common shares/units	(117,242)	(114,270)
Distributions paid on preferred shares/units	(922)	(922)
Net change in other financing activities	625	(1,108)
Net cash used in financing activities	(27,852)	(92,107)
Net increase (decrease) in cash, cash equivalents and restricted cash	7,760	(21,494)
Cash, cash equivalents and restricted cash, beginning of period	35,615	70,541
Cash, cash equivalents and restricted cash, end of period	43,375	49,047
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	32,620	34,508
Restricted cash	10,755	14,539
Cash, cash equivalents and restricted cash, end of period	43,375	49,047
Supplemental disclosure of cash flow information:
Interest paid	26,998	25,730
Income taxes paid	81	34
Supplemental disclosure of noncash investing and financing activities:
Conversion of OP Units to shares of common stock	232	450
Accrued construction in progress	32,781	25,878
Interest capitalized	2,550	1,391
Limited Partner [Member]
Cash flows from operating activities:
Net income	48,864	37,952
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	131,820	126,657
Loss on sale of depreciable real estate assets		29
Loss on sale of non-depreciable real estate assets		376
Loss on embedded derivative in preferred shares	15,108	27,638
Stock compensation expense	5,369	5,288
Amortization of debt issuance costs, discounts and premiums	1,344	1,157
Net change in operating accounts and other operating activities	(54,394)	(38,495)
Net cash provided by operating activities	148,111	160,602
Cash flows from investing activities:
Purchases of real estate and other assets		(5,004)
Capital improvements, development and other	(113,511)	(84,610)
Distributions from real estate joint ventures	114
Contributions to affiliates		(900)
Proceeds from disposition of real estate assets	898	525
Net cash used in investing activities	(112,499)	(89,989)
Cash flows from financing activities:
Proceeds from revolving credit facility		130,000
Repayments of revolving credit facility		(30,000)
Net proceeds from (repayments of) commercial paper	213,000	(70,000)
Principal payments on notes payable	(119,154)	(1,740)
Distributions paid on common shares/units	(121,401)	(118,337)
Distributions paid on preferred shares/units	(922)	(922)
Net change in other financing activities	625	(1,108)
Net cash used in financing activities	(27,852)	(92,107)
Net increase (decrease) in cash, cash equivalents and restricted cash	7,760	(21,494)
Cash, cash equivalents and restricted cash, beginning of period	35,615	70,541
Cash, cash equivalents and restricted cash, end of period	43,375	49,047
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	32,620	34,508
Restricted cash	10,755	14,539
Cash, cash equivalents and restricted cash, end of period	43,375	49,047
Supplemental disclosure of cash flow information:
Interest paid	26,998	25,730
Income taxes paid	81	34
Supplemental disclosure of noncash investing and financing activities:
Accrued construction in progress	32,781	25,878
Interest capitalized	$ 2,550	$ 1,391