Schedule of Mortgage-Backed Securities by Weighted Average Life (Details) - USD ($) $ in Thousands		Dec. 31, 2020	Dec. 31, 2019
Mortgage-Backed Securities [Line Items]
Mortgage-backed securities, at fair value(1)	[1]	$ 1,081,380	$ 1,401,778
Non-Agency RMBS [Member]
Mortgage-Backed Securities [Line Items]
Mortgage-backed securities, at fair value(1)		17,612	8,851
Amortized Cost		$ 15,369	$ 6,924
Weighted Average Coupon Rate, Percent		1.32%	3.73%
Less than three years [Member] | Non-Agency RMBS [Member]
Mortgage-Backed Securities [Line Items]
Mortgage-backed securities, at fair value(1)		$ 1,848	$ 4,000
Amortized Cost		$ 1,757	$ 3,823
Weighted Average Coupon Rate, Percent		2.08%	5.35%
Greater than three years and less than seven years [Member] | Non-Agency RMBS [Member]
Mortgage-Backed Securities [Line Items]
Mortgage-backed securities, at fair value(1)		$ 8,728	$ 784
Amortized Cost		$ 7,215	$ 307
Weighted Average Coupon Rate, Percent		1.45%	3.88%
Greater than seven years and less than eleven years [Member] | Non-Agency RMBS [Member]
Mortgage-Backed Securities [Line Items]
Mortgage-backed securities, at fair value(1)		$ 7,036	$ 4,067
Amortized Cost		$ 6,397	$ 2,794
Weighted Average Coupon Rate, Percent		0.93%	2.29%
Greater than eleven years [Member] | Non-Agency RMBS [Member]
Mortgage-Backed Securities [Line Items]
Mortgage-backed securities, at fair value(1)		$ 0	$ 0
Amortized Cost		$ 0	$ 0
Weighted Average Coupon Rate, Percent		0.00%	0.00%
Fixed Rate [Member] | Agency RMBS [Member]
Mortgage-Backed Securities [Line Items]
Mortgage-backed securities, at fair value(1)		$ 1,050,719	$ 1,374,683
Amortized Cost		$ 1,009,226	$ 1,351,210
Weighted Average Coupon Rate, Percent		3.75%	4.10%
Fixed Rate [Member] | Less than three years [Member] | Agency RMBS [Member]
Mortgage-Backed Securities [Line Items]
Mortgage-backed securities, at fair value(1)		$ 165,830	$ 53,620
Amortized Cost		$ 162,346	$ 52,683
Weighted Average Coupon Rate, Percent		3.80%	4.72%
Fixed Rate [Member] | Greater than three years and less than seven years [Member] | Agency RMBS [Member]
Mortgage-Backed Securities [Line Items]
Mortgage-backed securities, at fair value(1)		$ 860,498	$ 793,820
Amortized Cost		$ 824,259	$ 778,950
Weighted Average Coupon Rate, Percent		3.74%	4.18%
Fixed Rate [Member] | Greater than seven years and less than eleven years [Member] | Agency RMBS [Member]
Mortgage-Backed Securities [Line Items]
Mortgage-backed securities, at fair value(1)		$ 7,953	$ 496,334
Amortized Cost		$ 7,399	$ 488,956
Weighted Average Coupon Rate, Percent		3.86%	3.92%
Fixed Rate [Member] | Greater than eleven years [Member] | Agency RMBS [Member]
Mortgage-Backed Securities [Line Items]
Mortgage-backed securities, at fair value(1)		$ 16,438	$ 30,909
Amortized Cost		$ 15,222	$ 30,621
Weighted Average Coupon Rate, Percent		3.61%	3.97%
Interest-Only [Member] | Agency RMBS [Member]
Mortgage-Backed Securities [Line Items]
Mortgage-backed securities, at fair value(1)		$ 13,049	$ 18,244
Amortized Cost		$ 15,434	$ 17,795
Weighted Average Coupon Rate, Percent		3.25%	3.22%
Interest-Only [Member] | Less than three years [Member] | Agency RMBS [Member]
Mortgage-Backed Securities [Line Items]
Mortgage-backed securities, at fair value(1)		$ 3,345	$ 3,695
Amortized Cost		$ 4,341	$ 3,407
Weighted Average Coupon Rate, Percent		4.72%	4.53%
Interest-Only [Member] | Greater than three years and less than seven years [Member] | Agency RMBS [Member]
Mortgage-Backed Securities [Line Items]
Mortgage-backed securities, at fair value(1)		$ 9,612	$ 14,446
Amortized Cost		$ 10,995	$ 14,283
Weighted Average Coupon Rate, Percent		2.84%	2.93%
Interest-Only [Member] | Greater than seven years and less than eleven years [Member] | Agency RMBS [Member]
Mortgage-Backed Securities [Line Items]
Mortgage-backed securities, at fair value(1)		$ 92	$ 103
Amortized Cost		$ 98	$ 105
Weighted Average Coupon Rate, Percent		0.23%	0.33%
Interest-Only [Member] | Greater than eleven years [Member] | Agency RMBS [Member]
Mortgage-Backed Securities [Line Items]
Mortgage-backed securities, at fair value(1)		$ 0	$ 0
Amortized Cost		$ 0	$ 0
Weighted Average Coupon Rate, Percent		0.00%	0.00%

[1] Includes assets pledged as collateral to counterparties. See Note 6 for additional details on the Company's borrowings and related collateral.