CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 1,231	$ 64,906	$ 3,091	$ 4,867
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization			62,735	67,170
Straight-line rents			(2,765)	(2,888)
Non-cash lease expense			2,066	1,368
Net unrealized holding gains on investments			(8,565)	(64,937)
Distributions of operating income from unconsolidated affiliates			1,387	2,206
Equity in earnings of unconsolidated affiliates	(1,106)	786	(3,369)	(469)
Stock compensation expense			7,135	6,136
Amortization of financing costs			2,546	2,920
Impairment charges	0	0	0	51,549
Gain on disposition of properties	(5,909)	(485)	(10,521)	(485)
Allowance for credit loss			1,238	9,682
Termination of ground lease			(3,615)	0
Adjustments to straight-line rent reserves			511	6,493
Other, net			(4,127)	(2,780)
Changes in assets and liabilities:
Other liabilities			3,114	(6,684)
Lease liability - operating leases			(1,533)	(807)
Prepaid expenses and other assets			(487)	(4,213)
Rents receivable			2,801	(22,290)
Accounts payable and accrued expenses			(609)	12,222
Net cash provided by operating activities			51,033	59,060
CASH FLOWS FROM INVESTING ACTIVITIES
Acquisition of real estate			0	(21,208)
Development, construction and property improvement costs			(16,620)	(21,093)
Proceeds from the disposition of properties, net			63,901	13,925
Investments in and advances to unconsolidated affiliates and other			(3,976)	(3,270)
Return of capital from unconsolidated affiliates and other			7,717	7,151
Issuance of notes receivable			(15,995)	(59,000)
Return (payment) of deposits for properties under contract			(1,000)	187
Payment of deferred leasing costs			(3,080)	(4,885)
Change in control of previously unconsolidated affiliate			0	950
Net cash provided by (used in) investing activities			30,947	(87,243)
CASH FLOWS FROM FINANCING ACTIVITIES
Principal payments on mortgage and other notes			(52,408)	(14,360)
Principal payments on unsecured debt			(102,800)	(69,930)
Proceeds received on mortgage and other notes			8,818	3,340
Proceeds from unsecured debt			49,295	181,700
Payments of finance lease obligations			0	(833)
Proceeds from the sale (repurchase) of Common Shares			45,675	(22,386)
Capital contributions from noncontrolling interests			17,109	28,309
Distributions to noncontrolling interests			(12,202)	(8,178)
Dividends paid to Common Shareholders			(12,945)	(50,182)
Deferred financing and other costs			(6,707)	(960)
Net cash (used in) provided by financing activities			(66,165)	46,520
Increase in cash and restricted cash			15,815	18,337
Cash of $19,232 and $15,845 and restricted cash of $14,692 and $14,165, respectively, beginning of period			33,924	30,010	$ 30,010
Cash of $34,645 and $34,273 and restricted cash of $15,094 and $14,074, respectively, end of period	$ 49,739	$ 48,347	49,739	48,347	$ 33,924
Supplemental disclosure of cash flow information
Cash paid during the period for interest, net of capitalized interest of $1,832 and $4,656 respectively			20,666	26,558
Cash paid for income taxes, net of refunds			344	219
Supplemental disclosure of non-cash investing and financing activities
Right-of-use, assets operating leases modified in exchange for operating lease liabilities			412	0
Assumption of accounts payable and accrued expenses through acquisition of real estate			0	116
Distribution declared and payable on July 15, 2021 and 2020, respectively			14,314	123
Right-of-use assets, finance leases obtained in exchange for assets under capital lease			0	(70,427)
Right-of-use assets, operating leases exchanged for operating lease liabilities			0	1,432
Change in control of previously unconsolidated (consolidated) investment
Increase in real estate			0	(135,190)
Decrease in investments in and advances to unconsolidated affiliates			0	96,816
Change in other assets and liabilities			0	1,238
Acquisition of noncontrolling interest asset			0	(588)
Decrease in notes receivable			0	38,674
Increase in cash and restricted cash upon change of control			$ 0	$ 950