CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
CASH FLOW FROM OPERATING ACTIVITIES
Net loss	$ (10,933,000)	$ (30,975,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Equity in loss of unconsolidated entities	1,162,000	894,000
Distributions from unconsolidated entities	1,042,000	46,000
Gain on sale of real estate, net	(24,208,000)	(20,788,000)
Impairment of real estate assets	1,700,000	0
Share-based compensation	911,000	1,179,000
Depreciation and amortization	13,142,000	34,097,000
Amortization of deferred financing costs	106,000	106,000
Amortization of above and below market leases, net	(39,000)	(97,000)
Straight-line rent adjustment	210,000	2,701,000
Change in operating assets and liabilities
Tenants and other receivables	294,000	(2,300,000)
Prepaid expenses, deferred expenses and other assets	1,151,000	(124,000)
Accounts payable, accrued expenses and other liabilities	3,352,000	5,061,000
Net cash used in operating activities	(12,110,000)	(10,200,000)
CASH FLOW FROM INVESTING ACTIVITIES
Investment in unconsolidated entities	(9,902,000)	(16,894,000)
Distributions from unconsolidated entities		1,150,000
Net proceeds from sale of real estate	44,234,000	58,330,000
Development of real estate	(26,804,000)	(73,610,000)
Net cash provided by (used in) investing activities	7,528,000	(31,024,000)
CASH FLOW FROM FINANCING ACTIVITIES
Repayment of sale-leaseback financing obligations	157,000
Purchase of shares related to stock grant recipients' tax withholdings	(138,000)	(74,000)
Preferred dividends paid	(1,225,000)	(1,225,000)
Net cash used in financing activities	(1,206,000)	(1,299,000)
Net decrease in cash and cash equivalents	(5,788,000)	(42,523,000)
Cash and cash equivalents, and restricted cash, beginning of period	150,254,000	139,260,000
Cash and cash equivalents, and restricted cash, end of period	144,466,000	96,737,000
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash payments for interest	27,999,000	28,311,000
Capitalized interest	2,954,000	7,914,000
Income taxes paid (refunded)	(138,000)	5,000
SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES
Development of real estate financed with accounts payable	8,079,000	57,644,000
Preferred dividends declared and unpaid	1,225,000	1,225,000
Transfer to real estate assets held for sale	$ 22,577,000	(2,071,000)
Recording of right of use assets		1,598,000
Recording of lease liabilities		$ (1,598,000)