Condensed Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2019		Sep. 30, 2019		Jun. 30, 2019		Mar. 31, 2019		Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019		Dec. 31, 2018
Securitization Transactions [Line Items]
Interest income	$ 45,353		$ 39,985		$ 38,547		$ 36,016		$ 35,694	$ 35,300	$ 31,941	$ 28,092	$ 159,901		$ 131,027	[1]
Interest Expense	21,205		19,954		19,702		17,618		16,083	15,678	13,383	11,562	78,479		56,707
Interest income	45,353		39,985		38,547		36,016		35,694	35,300	31,941	28,092	159,901		131,027	[1]
Interest Expense	21,205		19,954		19,702		17,618		16,083	15,678	13,383	11,562	78,479		56,707
Interest Income (Expense), Net	24,148		20,031		18,845		18,398						81,422
Realized gains (losses) on securities and loans, financial derivatives, and real estate owned, net	(7,266)		(4,827)		(12,327)		(16,950)
Unrealized gains (losses) on securities and loans, financial derivatives, and real estate owned, net	6,139		7,970		13,300		20,452
Other, net	1,001		539		1,808		2,002						5,350
Noninterest Income	(126)		3,682		2,781		5,504						11,841
Base management fee to affiliate (Net of fee rebates)	2,663	[2]	1,942	[2]	1,661	[2]	1,722	[2]	1,744	1,830	2,021	1,978	7,988	[2]	7,573	[3]
Incentive Fee Expense	116		0		0		0		0	424	291	0	116		715
Debt issuance costs related to Other secured borrowings, at fair value	1,865		0		1,671		0						3,536		1,647
Other									4,201	4,384	3,771	2,952
Professional fees	1,021		698		1,178		1,956						4,853		3,902
Compensation expense	962		712		903		1,072						3,649		2,233
Other expenses									4,609	2,352	2,578	2,074
Operating Expenses	11,783		7,795		9,948		9,211		26,637	24,668	22,044	18,566	38,737		91,916
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	12,239		15,918		11,678		14,691						54,526
Income Tax Expense (Benefit)	1,180		2		376		0						1,558
Earnings from investments in unconsolidated entities	3,262		2,796		2,354		1,797						10,209
Net Income (Loss)	14,321		18,712		13,656		16,488						63,177
Net income (loss) attributable to non-controlling interests	1,733		1,419		1,012		1,080		1,147	813	991	285	5,244		3,235
Preferred Stock Dividends, Income Statement Impact	1,466		0		0		0						1,466
Net Income (Loss) Attributable to Common Stockholders	$ 11,122		$ 17,293		$ 12,644		$ 15,408		$ (2,217)	$ 6,661	$ 21,193	$ 21,039	$ 56,467		$ 46,676
Basic and Diluted (USD per share)	$ 0.31		$ 0.53		$ 0.43		$ 0.52		$ (0.07)	$ 0.22	$ 0.69	$ 0.67	$ 1.76		$ 1.52
Management Fee Expense, Rebates	$ 509		$ 503		$ 508		$ 447		$ 400	$ 400	$ 300	$ 300	$ 2,000	[2]
Other income									1,157	1,046	1,094	716			$ 4,014
Interest and Other Income									36,851	36,346	33,035	28,808			135,041
Operating Income (Loss)									10,214	11,678	10,991	10,242			43,125
Realized gain or loss on investments, financial derivatives, and foreign currency transactions (excludes FX on cash)									9,578	10,102	(1,343)	13,051			25,368
Total Net Unrealized Gain Loss On Investments, Other Secured Borrowings, Financial Derivatives, and Foreign Currency Translation (excluding FX on cash)									(20,862)	(14,306)	12,536	(1,969)			26,318
Investment Company, Realized and Unrealized Gain (Loss) on Investment and Foreign Currency									(11,284)	(4,204)	11,193	11,082			6,786
NET INCREASE IN EQUITY RESULTING FROM OPERATIONS									(1,070)	7,474	22,184	21,324			49,911
Consolidated Entities [Member]
Securitization Transactions [Line Items]
Interest income									2,100	1,300	1,300	1,300			6,000
Interest Expense									1,200	700	800	900			3,600
Interest income									2,100	1,300	1,300	1,300			6,000
Interest Expense									$ 1,200	$ 700	$ 800	$ 900			$ 3,600

[1] Includes interest income and interest expense of a consolidated securitization trust of $6.0 million and $3.6 million, respectively, for the year ended December 31, 2018. See Note 6 for further details on the Company's consolidated securitization trust.

[2] See Note 13 for further details on management fee rebates.

[3] See Note 9 for further details on management fee rebates.