Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ 345,521	$ 1,142	$ 379,758
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Deferred rent and amortization of intangible assets, liabilities and lease inducements	(2,727)	(3,636)	(2,172)
Depreciation and amortization	27,374	53,228	58,364
Reclassification from AOCI to interest expense	(1,806)	(1,552)	0
Reclassification from other assets to interest expense for swap termination	1,421	0	0
Change in fair value of swaps	209	1,728	0
Change in fair value of swaps		1,728
Transfer of right to collect supplemental real estate tax reimbursements	0	0	(5,097)
Gain on sale of real estate	(433,104)	0	(408,098)
Impairment of real estate	69,000	0	13,100
Loss on early extinguishment of debt	29,982	808	8,215
Straight-line rent, below-market ground lease and amortization of intangible assets	0	(18)	1,069
Straight-line lease termination income	0	0	(362)
Amortization of deferred loan costs	1,133	896	1,016
Amortization of premiums and discounts on debt	(227)	(444)	(590)
Unrealized premium adjustment	1,697	2,522	2,447
Amortization and accretion on loans receivable, net	(501)	(41)	96
Bad debt expense	40	494	677
Deferred income taxes	(81)	(3)	271
Stock-based compensation	194	162	154
Loans funded, held for sale to secondary market	(29,694)	(55,655)	(57,237)
Proceeds from sale of guaranteed loans	40,033	54,142	51,312
Principal collected on loans subject to secured borrowings	3,613	5,698	6,674
Other operating activity	(822)	(1,587)	(1,718)
Changes in operating assets and liabilities:
Accounts receivable and interest receivable	3,197	6,692	(977)
Other assets	2,980	(1,421)	(21,341)
Accounts payable and accrued expenses	(6,326)	(365)	(14,139)
Deferred leasing costs	(1,695)	(5,773)	(6,973)
Other liabilities	(6,825)	2,221	(5,589)
Due to related parties	(1,601)	2,218	(1,584)
Net cash provided by (used in) operating activities	40,985	61,456	(2,724)
CASH FLOWS FROM INVESTING ACTIVITIES:
Additions to investments in real estate	(24,600)	(12,055)	(21,101)
Acquisition of real estate	0	(112,048)	(19,631)
Proceeds from sale of real estate, net	941,032	0	1,018,476
Loans funded	(9,898)	(18,579)	(19,079)
Principal collected on loans	10,273	10,770	10,883
Other investing activity	386	178	317
Net cash provided by (used in) investing activities	917,193	(131,734)	969,865
CASH FLOWS FROM FINANCING ACTIVITIES:
Payment of unsecured revolving lines of credit, revolving credit facilities and term notes	(135,500)	(220,000)	(335,000)
Proceeds from unsecured revolving lines of credit, revolving credit facilities and term notes	158,500	180,000	120,000
Payment of mortgages payable	(46,000)	0	(65,877)
Investments in marketable securities in connection with the legal defeasance of mortgages payable	(268,194)	0	0
Prepayment penalties and other payments for early extinguishment of debt	(5,660)	0	(6,361)
Payment of principal on SBA 7(a) loan-backed notes	(11,487)	(4,431)	0
Proceeds from SBA 7(a) loan-backed notes	0	38,200	0
Payment of principal on secured borrowings	(3,613)	(5,698)	(6,674)
Proceeds from secured borrowings	0	772	0
Payment of deferred preferred stock offering costs	(1,320)	(1,136)	(3,832)
Payment of deferred loan costs	(34)	(4,234)	(304)
Payment of other deferred costs	(389)	(235)	0
Payment of common dividends	(13,140)	(21,895)	(38,327)
Payment of special cash dividends	(613,294)	(1,575)	(4,872)
Repurchase of Common Stock	0	0	(886,010)
Payment of borrowing costs	0	0	(8)
Net proceeds from issuance of Series A Preferred Warrants	385	73	127
Payment of preferred stock dividends	(22,157)	(2,173)	(250)
Retirement of fractional shares of Common Stock	(1)	0	0
Noncontrolling interests' distributions	(522)	(74)	(43)
Noncontrolling interests' contributions	455	0	0
Net cash used in financing activities	(1,000,157)	(6,535)	(989,011)
Change in cash balances included in assets held for sale	755	(755)	0
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS AND RESTRICTED CASH	(41,224)	(77,568)	(21,870)
CASH AND CASH EQUIVALENTS AND RESTRICTED CASH:
Beginning of period	77,171	154,739	176,609
End of period	35,947	77,171	154,739
RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH TO THE CONSOLIDATED BALANCE SHEETS:
Total cash and cash equivalents and restricted cash	35,947	77,171	154,739
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid during the period for interest	13,674	27,473	35,092
Federal income taxes paid	1,000	622	1,595
SUPPLEMENTAL DISCLOSURES OF NONCASH INVESTING AND FINANCING ACTIVITIES:
Additions to investments in real estate included in accounts payable and accrued expenses	5,663	11,875	9,024
Net increase in fair value of derivatives applied to other comprehensive income	0	1,727	2,140
Reduction of loans receivable and secured borrowings due to the SBA's repurchase of the guaranteed portion of loans	0	0	534
Additions to deferred loan costs included in accounts payable and accrued expenses	0	32	0
Additions to deferred costs included in accounts payable and accrued expenses	35	174	0
Additions to preferred stock offering costs included in accounts payable and accrued expenses	264	172	388
Accrual of dividends payable to preferred stockholders	9,873	14,935	249
Preferred stock offering costs offset against redeemable preferred stock in temporary equity	347	229	122
Preferred stock offering costs offset against redeemable preferred stock in permanent equity	3	0	2,532
Reclassification of Series A Preferred Stock from temporary equity to permanent equity	35,649	27,887	1,417
Reclassification of loans receivable, net to real estate owned	243	0	0
Reclassification of Series A Preferred Stock from temporary equity to accounts payable and accrued expenses	0	0	13
Reclassification of Series A Preferred Stock from permanent equity to accounts payable and accrued expenses	20	0	0
Accrual of special cash dividends	0	0	1,575
Accrual reversed to lease termination income	0	0	480
Payable to related parties included in net proceeds from disposition of real estate	0	0	202
Establishment of right-of-use asset and lease liability	362	0	0
Marketable securities transferred in connection with the legal defeasance of mortgages payable	268,194	0	0
Mortgage notes payable legally defeased	245,000	0	0
Mortgage note assumed in connection with our sale of real estate	28,200	0	0
Series A Preferred Stock
CASH FLOWS FROM FINANCING ACTIVITIES:
Net proceeds from issuance of Preferred Stock	37,197	35,984	28,070
Redemption of Series A Preferred Stock	(228)	(113)	(27)
Series L Preferred Stock
CASH FLOWS FROM FINANCING ACTIVITIES:
Net proceeds from issuance of Preferred Stock	0	0	210,377
Redemption of Series A Preferred Stock	$ (75,155)	$ 0	$ 0