Financial Derivatives (Schedule of Gains and Losses on Derivative Contracts) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Derivative [Line Items]
Net Realized Gains (Losses) on Periodic Settlements of Interest Rate Swaps	$ 6,721	$ 10,751	$ 17,539	$ 26,189
Net Realized Gains (Losses) Other Than Periodic Settlements of Interest Rate Swaps	(7,240)	(4,438)	(6,417)	(16,398)
Realized gains (losses) on financial derivatives, net	(519)	6,313	11,122	9,791
Change in Net Unrealized Gains (Losses) on Accrued Periodic Settlements of Interest Rate Swaps	2,267	(479)	180	(4,906)
Change in Net Unrealized Gains (Losses) Other Than on Accrued Periodic Settlements of Interest Rate Swaps	(27,875)	8,381	(52,904)	43,173
Unrealized gains (losses) on financial derivatives, net	(25,608)	7,902	(52,724)	38,267
Interest rate swaps | Interest Rate Risk [Member]
Derivative [Line Items]
Net Realized Gains (Losses) on Periodic Settlements of Interest Rate Swaps	6,721	10,751	17,539	26,189
Net Realized Gains (Losses) Other Than Periodic Settlements of Interest Rate Swaps	(1,321)	(12,875)	837	(21,528)
Realized gains (losses) on financial derivatives, net	5,400	(2,124)	18,376	4,661
Change in Net Unrealized Gains (Losses) on Accrued Periodic Settlements of Interest Rate Swaps	2,267	(479)	180	(4,906)
Change in Net Unrealized Gains (Losses) Other Than on Accrued Periodic Settlements of Interest Rate Swaps	(12,939)	9,854	(38,537)	33,745
Unrealized gains (losses) on financial derivatives, net	(10,672)	9,375	(38,357)	28,839
Credit default swaps on asset-backed indices | Credit Risk [Member]
Derivative [Line Items]
Net Realized Gains (Losses) Other Than Periodic Settlements of Interest Rate Swaps	(159)	(232)	42	(432)
Realized gains (losses) on financial derivatives, net	(159)	(232)	42	(432)
Change in Net Unrealized Gains (Losses) Other Than on Accrued Periodic Settlements of Interest Rate Swaps	466	189	352	(1,182)
Unrealized gains (losses) on financial derivatives, net	466	189	352	(1,182)
Credit default swaps on corporate bond indices | Credit Risk [Member]
Derivative [Line Items]
Net Realized Gains (Losses) Other Than Periodic Settlements of Interest Rate Swaps	(5,429)	(1,683)	(5,561)	(6,250)
Realized gains (losses) on financial derivatives, net	(5,429)	(1,683)	(5,561)	(6,250)
Change in Net Unrealized Gains (Losses) Other Than on Accrued Periodic Settlements of Interest Rate Swaps	(9,424)	1,833	(6,241)	3,509
Unrealized gains (losses) on financial derivatives, net	(9,424)	1,833	(6,241)	3,509
Credit default swaps on corporate bonds | Credit Risk [Member]
Derivative [Line Items]
Net Realized Gains (Losses) Other Than Periodic Settlements of Interest Rate Swaps	67	(8)	59	(15)
Realized gains (losses) on financial derivatives, net	67	(8)	59	(15)
Change in Net Unrealized Gains (Losses) Other Than on Accrued Periodic Settlements of Interest Rate Swaps	(72)	(19)	(86)	42
Unrealized gains (losses) on financial derivatives, net	(72)	(19)	(86)	42
Total return swaps | Equity Market/Credit Risk [Member]
Derivative [Line Items]
Net Realized Gains (Losses) Other Than Periodic Settlements of Interest Rate Swaps		17		37
Realized gains (losses) on financial derivatives, net		17		37
Change in Net Unrealized Gains (Losses) Other Than on Accrued Periodic Settlements of Interest Rate Swaps		(3)		(3)
Unrealized gains (losses) on financial derivatives, net		(3)		(3)
Options | Credit Risk [Member]
Derivative [Line Items]
Net Realized Gains (Losses) Other Than Periodic Settlements of Interest Rate Swaps	0		0
Realized gains (losses) on financial derivatives, net	0		0
Change in Net Unrealized Gains (Losses) Other Than on Accrued Periodic Settlements of Interest Rate Swaps	(3,991)		(3,832)
Unrealized gains (losses) on financial derivatives, net	(3,991)		(3,832)
TBA securities | Interest Rate Risk [Member]
Derivative [Line Items]
Net Realized Gains (Losses) Other Than Periodic Settlements of Interest Rate Swaps	(286)	3,113	(214)	3,929
Realized gains (losses) on financial derivatives, net	(286)	3,113	(214)	3,929
Change in Net Unrealized Gains (Losses) Other Than on Accrued Periodic Settlements of Interest Rate Swaps	(804)	477	(1,418)	4,426
Unrealized gains (losses) on financial derivatives, net	(804)	477	(1,418)	4,426
Futures | Interest Rate Risk [Member]
Derivative [Line Items]
Net Realized Gains (Losses) Other Than Periodic Settlements of Interest Rate Swaps	903	6,909	(139)	7,344
Realized gains (losses) on financial derivatives, net	903	6,909	(139)	7,344
Change in Net Unrealized Gains (Losses) Other Than on Accrued Periodic Settlements of Interest Rate Swaps	(747)	(3,810)	(2,548)	3,107
Unrealized gains (losses) on financial derivatives, net	(747)	(3,810)	(2,548)	3,107
Forwards | Currency risk [Member]
Derivative [Line Items]
Net Realized Gains (Losses) Other Than Periodic Settlements of Interest Rate Swaps	(1,015)	322	(1,441)	432
Realized gains (losses) on financial derivatives, net	(1,015)	322	(1,441)	432
Change in Net Unrealized Gains (Losses) Other Than on Accrued Periodic Settlements of Interest Rate Swaps	(364)	(140)	(586)	255
Unrealized gains (losses) on financial derivatives, net	(364)	(140)	(586)	255
Warrants | Credit Risk [Member]
Derivative [Line Items]
Net Realized Gains (Losses) Other Than Periodic Settlements of Interest Rate Swaps	0	0	0	86
Realized gains (losses) on financial derivatives, net	0	0	0	86
Change in Net Unrealized Gains (Losses) Other Than on Accrued Periodic Settlements of Interest Rate Swaps	0	0	(8)	(726)
Unrealized gains (losses) on financial derivatives, net	$ 0	$ 0	$ (8)	$ (726)