Consolidated Statements of Cash Flows - USD ($)	3 Months Ended				6 Months Ended		45 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net (loss) income	$ (4,041,000)	$ (1,256,000)	$ 52,567,000	$ 291,623,000	$ (5,297,000)	$ 344,190,000
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred rent and amortization of intangible assets, liabilities and lease inducements					(1,341,000)	(999,000)
Depreciation and amortization	5,197,000		7,185,000		10,455,000	16,815,000
Reclassification from AOCI to interest expense			0		0	(1,806,000)
Reclassification from other assets to interest expense for swap termination					0	1,421,000
Change in fair value of swaps					0	209,000
Gain on sale of real estate	0		(55,221,000)		0	(432,802,000)
Impairment of real estate	0		2,800,000	66,200,000	0	69,000,000
Loss on early extinguishment of debt	0		4,911,000		0	29,982,000
Amortization of deferred loan costs					548,000	590,000
Amortization of premiums and discounts on debt					(51,000)	(10,000)
Unrealized premium adjustment					518,000	1,007,000
Accretion (Amortization) of Discounts and Premiums, Investments					(261,000)	(247,000)
Bad debt expense (recovery)					302,000	(63,000)
Deferred income taxes					(867,000)	(9,000)
Stock-based compensation					112,000	82,000
Loans funded, held for sale to secondary market					(9,303,000)	(13,892,000)
Proceeds from sale of guaranteed loans					10,902,000	23,826,000
Principal collected on loans subject to secured borrowings					2,613,000	461,000
Other operating activity					(407,000)	(386,000)
Changes in operating assets and liabilities:
Accounts receivable and interest receivable					586,000	817,000
Other assets					578,000	774,000
Accounts payable and accrued expenses					(2,902,000)	(2,208,000)
Deferred leasing costs					(332,000)	(934,000)
Other liabilities					(1,554,000)	(7,142,000)
Due to related parties					942,000	(3,739,000)
Net cash provided by operating activities					5,241,000	24,937,000
CASH FLOWS FROM INVESTING ACTIVITIES:
Additions to investments in real estate					(9,545,000)	(16,103,000)
Proceeds from sale of real estate, net					0	765,116,000
Loans funded					(18,567,000)	(4,631,000)
Principal collected on loans					4,710,000	4,254,000
Other investing activity					59,000	319,000
Net cash (used in) provided by investing activities					(23,343,000)	748,955,000
CASH FLOWS FROM FINANCING ACTIVITIES:
Payment of unsecured revolving lines of credit, revolving credit facility and or term note					(5,000,000)	(130,000,000)
Proceeds from unsecured revolving lines of credit, revolving credit facility and or term note					61,500,000	0
Payment of mortgages payable					0	(46,000,000)
Investments in marketable securities in connection with the legal defeasance of mortgages payable					0	(268,194,000)
Prepayment penalties and other payments for early extinguishment of debt					0	(5,660,000)
Payment of principal on SBA 7(a) loan-backed notes					(5,370,000)	(6,397,000)
Borrowed funds from the Federal Reserve through the Paycheck Protection Program Liquidity Facility					15,466,000	0
Payment of principal on secured borrowings					(2,613,000)	(461,000)
Payment of deferred preferred stock offering costs					(501,000)	(336,000)
Payment of deferred loan costs					(70,000)	(34,000)
Payment of other deferred costs					(133,000)	(195,000)
Payment of common dividends					(2,207,000)	(10,950,000)
Net proceeds from issuance of Series A Preferred Warrants					29,000	40,000
Payment of preferred stock dividends					(12,589,000)	(15,945,000)
Redemption of Series A Preferred Stock					(1,626,000)	(153,000)
Noncontrolling interests' distributions					(45,000)	(47,000)
Net cash provided by (used in) financing activities					68,307,000	(466,851,000)
Change in cash balances included in assets held for sale					0	(1,295,000)
NET INCREASE IN CASH AND CASH EQUIVALENTS AND RESTRICTED CASH					50,205,000	305,746,000
CASH AND CASH EQUIVALENTS AND RESTRICTED CASH:
Beginning of period		35,947,000		77,171,000	35,947,000	77,171,000
End of period	86,152,000		382,917,000		86,152,000	382,917,000	$ 86,152,000
RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH TO THE CONSOLIDATED BALANCE SHEETS:
Cash and cash equivalents								$ 75,192,000	$ 23,801,000	$ 372,093,000
Restricted cash								10,960,000	12,146,000	10,824,000
Total cash and cash equivalents and restricted cash	86,152,000	35,947,000	382,917,000	77,171,000	86,152,000	382,917,000	86,152,000	86,152,000	$ 35,947,000	382,917,000
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid during the period for interest					5,567,000	8,499,000
Federal income taxes paid					100,000	700,000
SUPPLEMENTAL DISCLOSURES OF NONCASH INVESTING AND FINANCING ACTIVITIES:
Additions to investments in real estate included in accounts payable and accrued expenses					3,761,000	1,292,000
Additions to deferred costs included in accounts payable and accrued expenses					292,000	79,000
Additions to preferred stock offering costs included in accounts payable and accrued expenses					616,000	355,000
Accrual of dividends payable to preferred stockholders								$ 2,428,000		$ 1,150,000
Preferred stock offering costs offset against redeemable preferred stock in temporary equity					303,000	122,000
Preferred stock offering costs offset against redeemable preferred stock in permanent equity					2,000	0
Reclassification of Series A Preferred Stock from temporary equity to permanent equity	9,739,000	6,948,000	$ 10,825,000	$ 8,890,000	16,687,000	19,715,000	$ 81,640,000
Additions to deferred loan costs included in accounts payable and accrued expenses					165,000	0
Reclassification of loans receivable, net to real estate owned					174,000	243,000
Establishment of right-of use asset and lease liability					0	362,000
Marketable securities transferred in connection with the legal defeasance of mortgages payable					0	268,194,000
Mortgage notes payable legally defeased					0	245,000,000
Mortgage note assumed in connection with our sale of real estate					0	28,200,000
Redeemable preferred stock deemed dividends	$ 52,000	$ 161,000			213,000	0
Issuance of shares of Common Stock for asset management fees					2,359,000	0
Series A Preferred Stock
CASH FLOWS FROM FINANCING ACTIVITIES:
Net proceeds from issuance of Series Preferred Stock					21,296,000	17,481,000
SUPPLEMENTAL DISCLOSURES OF NONCASH INVESTING AND FINANCING ACTIVITIES:
Redeemable Preferred Stock fees included in accounts payable and accrued expenses					247,000	0
Series D Preferred Stock
CASH FLOWS FROM FINANCING ACTIVITIES:
Net proceeds from issuance of Series Preferred Stock					170,000	0
SUPPLEMENTAL DISCLOSURES OF NONCASH INVESTING AND FINANCING ACTIVITIES:
Redeemable Preferred Stock fees included in accounts payable and accrued expenses					$ 2,000	$ 0