CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES
Net (loss) income	$ (66,038)	$ 21,204	$ (15,698)
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation and amortization	149,793	125,443	117,549
Straight-line rents	(5,096)	(5,198)	(8,616)
Noncash lease expense	3,392
Net unrealized holding gains on investments	(72,391)
Distributions of operating income from unconsolidated affiliates	3,286	11,273	15,556
Equity in earnings and gains of unconsolidated affiliates	1,237	(8,922)	(9,302)
Stock compensation expense	10,912	10,957	12,948
Amortization of financing costs	5,169	7,577	6,008
Impairment charges	85,598	1,721
Gain on disposition of properties	(683)	(30,324)	(5,140)
Gain on debt extinguishment	(18,339)
Allowance for credit loss	24,770	2,625	(87)
Adjustments to straight-line rent reserves	22,074	1,776	2,620
Deferred gain on tax credits		(5,034)
Other, net	(8,753)	(11,627)	(11,768)
Changes in assets and liabilities:
Other liabilities	(4,208)	(4,466)	6,161
Lease liability - operating leases	(1,579)
Prepaid expenses and other assets	32	8,198	(7,168)
Rents receivable, net	(29,810)	342	(3,961)
Accounts payable and accrued expenses	3,199	1,632	(3,026)
Net cash provided by operating activities	102,565	127,177	96,076
CASH FLOWS FROM INVESTING ACTIVITIES
Acquisition of real estate	(21,208)	(319,673)	(147,985)
Acquisition of leasehold interests		(39,031)
Development, construction and property improvement costs	(40,483)	(89,270)	(94,834)
Proceeds from the disposition of properties, net	20,930	88,738	63,866
Investments in and advances to unconsolidated affiliates and other	(4,291)	(151,281)	(3,161)
Return of capital from unconsolidated affiliates and other	14,686	105,999	26,338
Issuance of or advances on notes receivable	(59,000)	(3,608)	(3,002)
Proceeds from notes receivable		15,250	26,000
Return of deposits for properties under contract	187	2,870	1,692
Payment of deferred leasing costs	(7,979)	(7,051)	(6,106)
Change in control of previously unconsolidated affiliate	950		573
Net cash used in investing activities	(96,208)	(397,057)	(136,619)
CASH FLOWS FROM FINANCING ACTIVITIES
Principal payments on mortgage and other notes	(55,449)	(168,211)	(81,726)
Principal payments on unsecured debt	(136,490)	(521,600)	(632,300)
Proceeds received on mortgage and other notes	7,261	326,268	187,173
Proceeds from unsecured debt	236,804	526,400	648,800
Payments of finance lease obligations	(903)	(2,749)
(Repurchase) proceeds from the sale of Common Shares	(22,386)	145,498	(55,111)
Capital contributions from noncontrolling interests	52,674	161,628	47,560
Distributions to noncontrolling interests	(31,461)	(101,370)	(31,568)
Dividends paid to Common Shareholders	(50,182)	(93,902)	(88,887)
Deferred financing and other costs	(2,311)	(6,920)	(4,219)
Net cash (used in) provided by financing activities	(2,443)	265,042	(10,278)
Increase (decrease) in cash and restricted cash	3,914	(4,838)	(50,821)
Cash of $15,845, $21,268 and $74,823 and restricted cash of $14,165, $13,580 and $10,846, respectively, beginning of year	30,010	34,848	85,669
Cash of $19,232, $15,845 and $21,268 and restricted cash of $14,692, $14,165 and $13,580, respectively, end of year	33,924	30,010	34,848
Supplemental disclosure of cash flow information
Cash paid during the period for interest, net of capitalized interest of $7,110 and $12,586 and $5,625 respectively	72,392	53,586	61,832
Cash (received) paid for income taxes, net of refunds	(329)	730	1,227
Supplemental disclosure of non-cash investing and financing activities
Assumption of accounts payable and accrued expenses through acquisition of real estate	116	4,666	2,597
Notes receivable exchanged for real estate	72,430	13,530	22,201
Adjustment to equity as a result of the CECL implementation	400
Distribution declared and payable on January 15, 2020		26,914
Right-of-use assets, finance leases (modified) obtained in exchange for finance lease liabilities	(70,427)	16,349
Right-of-use assets, finance leases obtained in exchange for assets under capital lease		76,965
Right-of-use assets, operating leases obtained in exchange for operating lease liabilities	33,189	57,165
Capital lease obligation exchanged for finance lease liability		71,111
Other liabilities exchanged for operating lease liabilities		946
Assumption of debt through investments in unconsolidated affiliates		4,688
Debt exchanged for deferred gain on tax credits		(5,262)
Other assets exchanged for deferred gain on tax credits		228
Right of use assets, operating leases modified in exchange for finance lease liabilities	(1,432)
Change in control of previously unconsolidated (consolidated) investment
Increase in real estate	(135,190)	828	(31,836)
Decrease in investments in and advances to unconsolidated affiliates	96,816	(1,189)	35,881
Change in other assets and liabilities	1,238	12	(3,472)
Acquisition of noncontrolling interest asset	(588)
Decrease in notes receivable	38,674
Decrease in right-of-use assets, finance leases		11,051
Decrease in finance lease liability		$ (10,702)
Increase in cash and restricted cash upon change of control	$ 950		$ 573