Condensed Consolidated Statement of Cash Flows $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)		Dec. 31, 2019 USD ($)		Dec. 31, 2018 USD ($)
Statement of Cash Flows [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 28,377		$ 63,177		$ 49,911
Reconciliation of the net increase (decrease) in equity resulting from operations to net cash provided by (used in) operating activities:
Amortization of premiums and accretion of discounts, net	41,681		48,132		45,895
Realized (gains) losses on securities and loans, net	5,960		12,785
Realized (gains) losses on financial derivatives, net	31,521		30,912
Realized (gains) losses on real estate owned, net	(15)		(2,327)
Unrealized (gains) losses on securities and loans, net	25,783		(54,478)
Unrealized (gains) losses on financial derivatives, net	(989)		5,338
Unrealized (gains) losses on real estate owned, net	649		1,279
Unrealized (gains) losses other, net	9,562		645
Realized (gains) losses other, net—foreign currency transaction	173		2,392		(4,131)
Unrealized (gains) losses other, net—foreign currency translation	(1,720)		(3,310)
Purchase of investments					(3,350,398)
Proceeds from disposition of investments					1,868,532
Proceeds from principal payments of investments					497,858
Repurchase of investments sold short					(2,457,148)
Payments on financial derivatives					(119,490)
Proceeds from financial derivatives					121,904
Amortization of deferred debt issuance costs	263		263		263
Shares Issued In Connection With Incentive Fee Payment	12		0		71
Share-based long term incentive plan unit expense	722		475		415
Interest income related to consolidated securitization trust	(21,800)		(16,034)		4,697	[1]
Interest expense related to consolidated securitization trust	21,020		15,136		4,313	[1]
Debt issuance costs related to Other secured borrowings, at fair value	(1,749)		(1,381)
(Earnings) losses from investments in unconsolidated entities	(37,933)		(10,209)
Repurchase agreements					94,675
(Increase) decrease in assets:
Increase decrease in interest and principal receivable	5,223		(15,449)
Receivable for securities sold and financial derivatives					(304,826)
Due from brokers, net					68,610
Interest and principal receivable					(7,988)
Other assets	1,077		(3,663)		28,234
Increase (decrease) in liabilities:
Due to brokers					3,832
Payable for securities purchased and financial derivatives					285,708
Base management fee payable to affiliate	515		919		(369)
Accounts payable and accrued expenses					1,838
Incentive fee payable to affiliate	(116)		116
Other liabilities					(17)
Interest and dividends payable					1,255
Increase (decrease) in interest payable	(3,798)		161
Increase (decrease) in accrued expenses and other liabilities	11,590		1,607
Net cash provided by (used in) operating activities	119,506		79,248		(494,181)
Cash Flows from Investing Activities:
Purchase of securities	(1,346,245)		(3,057,372)
Purchase of loans	(852,261)		(1,040,006)
Capital improvements of real estate owned	(153)		(240)
Proceeds from disposition of securities	1,888,099		1,838,182
Proceeds from disposition of loans	25,414		28,878
Contributions to investments in unconsolidated entities	(34,624)		(42,124)
Distributions from investments in unconsolidated entities	30,644		49,758
Proceeds from disposition of real estate owned	9,889		24,059
Proceeds from principal payments of securities	362,987		275,221
Proceeds from principal payments of loans	443,640		304,953
Proceeds from investments sold short	268,294		645,553		2,674,841
Repurchase of securities sold short	(310,559)		(650,576)
Payments on financial derivatives	(115,418)		(90,057)
Proceeds from financial derivatives	84,597		58,578
Payments made on reverse repurchase agreements	(7,586,769)		(7,050,581)
Proceeds from reverse repurchase agreements	7,622,670		7,038,216
Due from brokers, net	16,443		6,483
Due to brokers, net	619		(3,458)
Net cash provided by (used in) investing activities	507,267		(1,664,533)
Cash flows provided by (used in) financing activities:
Net proceeds from issuance of common stock	95,537	[2]	156,742	[2]
Offering costs paid	(253)		(712)
Repurchase of common stock	(3,056)		(782)		(23,131)
Dividends paid	(65,026)		(54,312)		(50,736)
Contributions from non-controlling interests	9,848		27,650		21,532
Distributions to non-controlling interests	(11,301)		(23,063)		(23,853)
Proceeds from issuance of securitized debt	57,863		97,642		100,010
Proceeds from issuance of Other secured borrowings	427,959		250,666		102,706
Repayments of Secured Debt	(112,253)		(62,608)
Principal payment on securitized debt	(67,325)		(61,408)		(43,819)
Debt issuance costs related to Other secured borrowings at fair value financing activities					(775)
Borrowings under repurchase agreements	4,138,940		9,047,746		8,078,468
Repayments of repurchase agreements	(5,059,445)		(7,862,227)		(7,668,798)
Due from brokers, net	49		(13,676)
Due to brokers, net	1,035		(355)
Net cash provided by (used in) financing activities	(587,428)		1,612,681		491,604
Net Increase (Decrease) in Cash, Cash Equivalents, and Restricted Cash	39,345		27,396		(2,577)
Cash, Cash Equivalents, and Restricted Cash, Beginning of Period	72,477		45,081		47,658
Cash, Cash Equivalents, and Restricted Cash, End of Period	111,822		72,477		45,081
Supplemental disclosure of cash flow information:
Interest paid	65,751		78,754		55,649
Dividends payable	5,738		6,978
Contribution from non-controlling interest (non-cash)	2,340		0		9,537
Distributions to non-controlling interests	(2,340)		0
Shares Issued In Connection With Incentive Fee Payment Non-Cash	12		0		71
Income tax paid	543		189
Share-based long term incentive plan unit awards (non-cash)	722		475		415
Transfers from mortgage loans to real estate owned (non-cash)	3,384		22,577
Transfers from mortgage loans to investments in non-consolidated entities (non-cash)	10,833		0
Purchase of investments (non-cash)	0		(2,975)		17,424
Contributions to investments in non-consolidated entities (non-cash)	(17,023)		0
Purchase of Loans Non Cash	6,670		0
Proceeds from issuance of Other secured borrowings (non-cash)	6,670		0
Proceeds from principal payments of investments (non-cash)	193,575		119,683		49,731
Proceeds from the disposition of loans (non-cash)	113,791		0
Repayments of repurchase agreement (non-cash)	(27,864)		(226,945)
Principal payments on Other secured borrowings, at fair value (non-cash)	(193,575)		(119,683)		(49,731)
Proceeds received from Other secured borrowings, at fair value (non-cash)	28,818		227,428		120,625
Repayment of senior notes (non-cash)	0		(86,000)
Issuance of senior notes (non-cash)	0		86,000
Realized gain or loss on investments, financial derivatives, and foreign currency transactions (excludes FX on cash)					(25,368)
Total Net Unrealized Gain Loss On Investments, Other Secured Borrowings, Financial Derivatives, and Foreign Currency Translation (excluding FX on cash)					26,318
Debt issuance costs related to Other secured borrowings, at fair value	3,894		3,536		1,647	[1]
Aggregate To Be Announced Trade Activity Buys Sells Non Cash					29,752,907
Proceeds from the Disposition of Investments Non Cash					17,424
Repayments of reverse repurchase agreements non cash					(120,136)
Debt issuance costs related to Other secured borrowings at fair value non cash					(872)
Share based long term incentive plan unit redemption non cash					$ (9,537)
Proceeds from Issuance of Preferred Stock and Preference Stock	0		111,378
Distributions from investments in unconsolidated entities	0		2,975
Principal payments on Other secured borrowings (non-cash)	$ (96,480)		$ 0

[1] Related to non-qualified mortgage securitization transactions. See Note 6 for further details.

[2] Net of underwriters' discounts.