Condensed Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2020 |
Sep. 30, 2020 |
Jun. 30, 2020 |
Mar. 31, 2020 |
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, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
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| Text Block [Abstract] | |||||||||||||||||||||||||||
| Interest income | $ 39,067 | $ 43,075 | $ 39,281 | $ 52,108 | $ 45,353 | $ 39,985 | $ 38,547 | $ 36,016 | $ 35,694 | $ 35,300 | $ 31,941 | $ 28,092 | $ 173,531 | $ 159,901 | $ 131,027 | [1] | |||||||||||
| Interest expense | (11,952) | (12,937) | (14,686) | (22,090) | (21,205) | (19,954) | (19,702) | (17,618) | (16,083) | (15,678) | (13,383) | (11,562) | (61,665) | (78,479) | (56,707) | [1] | |||||||||||
| Interest Income (Expense), Net | 27,115 | 30,138 | 24,595 | 30,018 | 24,148 | 20,031 | 18,845 | 18,398 | 111,866 | 81,422 | |||||||||||||||||
| Realized gains (losses) on securities and loans, financial derivatives, and real estate owned, net | (9,551) | (192) | (27,927) | 204 | (7,266) | (4,827) | (12,327) | (16,950) | |||||||||||||||||||
| Unrealized gains (losses) on securities and loans, financial derivatives, and real estate owned, net | 42,547 | 24,032 | 52,057 | (144,079) | 6,139 | 7,970 | 13,300 | 20,452 | |||||||||||||||||||
| Other, net | (795) | (2,747) | (435) | 1,679 | 1,001 | 539 | 1,808 | 2,002 | (2,298) | 5,350 | |||||||||||||||||
| Noninterest Income | 32,201 | 21,093 | 23,695 | (142,196) | (126) | 3,682 | 2,781 | 5,504 | (65,207) | 11,841 | |||||||||||||||||
| Base management fee to affiliate (Net of fee rebates) | 3,178 | [2] | 2,981 | 2,906 | 2,443 | 2,663 | 1,942 | 1,661 | 1,722 | 1,744 | 1,830 | 2,021 | 1,978 | 11,508 | [2] | 7,988 | [2] | 7,573 | [3] | ||||||||
| Incentive Fee Expense | 0 | 0 | 0 | 0 | 116 | 0 | 0 | 0 | 0 | 424 | 291 | 0 | 0 | 116 | 715 | ||||||||||||
| Servicing expense | 1,736 | 2,379 | 2,493 | 2,531 | 2,055 | 1,940 | 2,244 | 2,393 | 9,139 | 8,632 | 7,715 | ||||||||||||||||
| Debt issuance costs related to Other secured borrowings, at fair value | 1,819 | 0 | 2,075 | 0 | 1,865 | 0 | 1,671 | 0 | 3,894 | 3,536 | 1,647 | [4] | |||||||||||||||
| Other | 1,782 | 1,199 | 707 | 1,423 | 1,941 | 1,347 | 1,238 | 1,083 | 5,111 | 5,609 | 7,592 | ||||||||||||||||
| Professional fees | 1,186 | 1,209 | 1,333 | 1,277 | 1,021 | 698 | 1,178 | 1,956 | 5,005 | 4,853 | 3,902 | ||||||||||||||||
| Compensation expense | 962 | 1,085 | 941 | 788 | 962 | 712 | 903 | 1,072 | 3,776 | 3,649 | 2,233 | ||||||||||||||||
| Other expenses | 1,531 | 1,625 | 1,497 | 1,752 | 1,160 | 1,156 | 1,053 | 985 | 6,405 | 4,354 | 1,898 | ||||||||||||||||
| Operating Expenses | 12,194 | 10,478 | 11,952 | 10,214 | 11,783 | 7,795 | 9,948 | 9,211 | 26,637 | 24,668 | 22,044 | 18,566 | 44,838 | 38,737 | 91,916 | ||||||||||||
| Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest | 47,122 | 40,753 | 36,338 | (122,392) | 12,239 | 15,918 | 11,678 | 14,691 | 1,821 | 54,526 | |||||||||||||||||
| Income Tax Expense (Benefit) | 7,888 | 2,494 | 1,542 | (547) | 1,180 | 2 | 376 | 0 | 11,377 | 1,558 | |||||||||||||||||
| Earnings (losses) from investments in unconsolidated entities | 27,344 | 11,443 | 5,643 | (6,497) | 3,262 | 2,796 | 2,354 | 1,797 | 37,933 | 10,209 | |||||||||||||||||
| Net Income (Loss), Including Portion Attributable to Noncontrolling Interest, Total | 66,578 | 49,702 | 40,439 | (128,342) | 14,321 | 18,712 | 13,656 | 16,488 | (1,070) | 7,474 | 22,184 | 21,324 | 28,377 | 63,177 | 49,911 | ||||||||||||
| Net income (loss) attributable to non-controlling interests | 1,475 | 1,559 | 1,220 | (885) | 1,733 | 1,419 | 1,012 | 1,080 | 1,147 | 813 | 991 | 285 | 3,369 | 5,244 | 3,235 | ||||||||||||
| Dividends on preferred stock | 1,941 | 1,940 | 1,941 | 1,941 | 1,466 | 0 | 0 | 0 | 7,763 | 1,466 | |||||||||||||||||
| Net income (loss) attributable to common stockholders | $ 63,162 | $ 46,203 | $ 37,278 | $ (129,398) | $ 11,122 | $ 17,293 | $ 12,644 | $ 15,408 | $ (2,217) | $ 6,661 | $ 21,193 | $ 21,039 | $ 17,245 | $ 56,467 | $ 46,676 | ||||||||||||
| Basic and Diluted (USD per share) | $ 1.44 | $ 1.06 | $ 0.85 | $ (3.04) | $ 0.31 | $ 0.53 | $ 0.43 | $ 0.52 | $ (0.07) | $ 0.22 | $ 0.69 | $ 0.67 | $ 0.39 | $ 1.76 | $ 1.52 | ||||||||||||
| Other income | $ 1,157 | $ 1,046 | $ 1,094 | $ 716 | $ 4,014 | ||||||||||||||||||||||
| Total investment income | 36,851 | 36,346 | 33,035 | 28,808 | 135,041 | ||||||||||||||||||||||
| Other investment related expenses | 4,201 | 4,384 | 3,771 | 2,952 | |||||||||||||||||||||||
| Other operating expenses | 4,609 | 2,352 | 2,578 | 2,074 | |||||||||||||||||||||||
| Net investment income | 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 Income (Loss), Including Portion Attributable to Noncontrolling Interest | $ 66,578 | $ 49,702 | $ 40,439 | $ (128,342) | $ 14,321 | $ 18,712 | $ 13,656 | $ 16,488 | (1,070) | 7,474 | 22,184 | 21,324 | $ 28,377 | $ 63,177 | $ 49,911 | ||||||||||||
| Management Fee Expense, Rebates | $ 400 | $ 400 | $ 300 | $ 300 | $ 1,051 | $ 1,967 | [2] | ||||||||||||||||||||
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