Investment in Securities (Summary of Investment in Securities) (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
		Mar. 31, 2023	Dec. 31, 2022
Securities, Available-for-sale [Line Items]
Current Principal		$ 1,429,611	$ 1,466,617
Unamortized Premium (Discount)		(189,626)	(164,198)
Amortized Cost		1,340,721	1,399,411
Gross Unrealized Gains		31,600	30,549
Gross Unrealized Losses		(141,076)	(179,698)
Investment Owned At Fair Value, Net		1,231,245	1,250,262
Securities, at fair value(1)(2)	[1],[2]	1,389,547	1,459,465
Securities sold short, at fair value		$ (158,302)	$ (209,203)
Weighted Average
Securities, Available-for-sale [Line Items]
Weighted Average Coupon		1.44%	1.58%
Weighted Average Yield		4.97%	4.41%
Weighted average life		6 years 3 months 7 days	6 years 8 months 1 day
Long
Securities, Available-for-sale [Line Items]
Current Principal		$ 1,597,619	$ 1,692,787
Unamortized Premium (Discount)		(190,404)	(168,822)
Amortized Cost		1,507,951	1,620,957
Gross Unrealized Gains		22,646	17,475
Gross Unrealized Losses		(141,050)	(178,967)
Securities, at fair value(1)(2)		$ 1,389,547	$ 1,459,465
Long | Weighted Average
Securities, Available-for-sale [Line Items]
Weighted Average Coupon		1.45%	1.59%
Weighted Average Yield		5.31%	4.70%
Weighted average life		6 years 7 months 2 days	6 years 11 months 4 days
Long | 15-year fixed-rate mortgages
Securities, Available-for-sale [Line Items]
Current Principal		$ 82,439	$ 140,409
Unamortized Premium (Discount)		1,090	4,613
Amortized Cost		83,529	145,022
Gross Unrealized Gains		111	0
Gross Unrealized Losses		(6,554)	(14,892)
Securities, at fair value(1)(2)		$ 77,086	$ 130,130
Long | 15-year fixed-rate mortgages | Weighted Average
Securities, Available-for-sale [Line Items]
Weighted Average Coupon		2.55%	2.59%
Weighted Average Yield		2.04%	1.73%
Weighted average life		3 years 11 months 1 day	4 years 3 months 18 days
Long | 20-year fixed-rate mortgages
Securities, Available-for-sale [Line Items]
Current Principal		$ 7,023	$ 7,253
Unamortized Premium (Discount)		366	380
Amortized Cost		7,389	7,633
Gross Unrealized Gains		0	0
Gross Unrealized Losses		(1,194)	(1,301)
Securities, at fair value(1)(2)		$ 6,195	$ 6,332
Long | 20-year fixed-rate mortgages | Weighted Average
Securities, Available-for-sale [Line Items]
Weighted Average Coupon		2.41%	2.41%
Weighted Average Yield		1.57%	1.57%
Weighted average life		6 years 9 months 7 days	6 years 11 months 12 days
Long | 30-year fixed-rate mortgages
Securities, Available-for-sale [Line Items]
Current Principal		$ 761,446	$ 846,582
Unamortized Premium (Discount)		14,982	20,961
Amortized Cost		776,428	867,543
Gross Unrealized Gains		1,185	228
Gross Unrealized Losses		(57,240)	(89,105)
Securities, at fair value(1)(2)		$ 720,373	$ 778,666
Long | 30-year fixed-rate mortgages | Weighted Average
Securities, Available-for-sale [Line Items]
Weighted Average Coupon		3.78%	3.54%
Weighted Average Yield		3.33%	3.12%
Weighted average life		7 years 8 months 26 days	8 years 6 months 25 days
Long | Adjustable rate mortgages
Securities, Available-for-sale [Line Items]
Current Principal		$ 5,952	$ 6,410
Unamortized Premium (Discount)		574	581
Amortized Cost		6,526	6,991
Gross Unrealized Gains		0	0
Gross Unrealized Losses		(645)	(737)
Securities, at fair value(1)(2)		$ 5,881	$ 6,254
Long | Adjustable rate mortgages | Weighted Average
Securities, Available-for-sale [Line Items]
Weighted Average Coupon		3.49%	3.41%
Weighted Average Yield		2.22%	2.20%
Weighted average life		4 years 8 months 19 days	4 years 9 months 14 days
Long | Reverse mortgages
Securities, Available-for-sale [Line Items]
Current Principal		$ 28,159	$ 29,658
Unamortized Premium (Discount)		3,486	3,511
Amortized Cost		31,645	33,169
Gross Unrealized Gains		0	0
Gross Unrealized Losses		(3,007)	(3,180)
Securities, at fair value(1)(2)		$ 28,638	$ 29,989
Long | Reverse mortgages | Weighted Average
Securities, Available-for-sale [Line Items]
Weighted Average Coupon		4.17%	3.50%
Weighted Average Yield		2.61%	2.60%
Weighted average life		4 years 11 months 4 days	4 years 10 months 2 days
Long | Interest only securities
Securities, Available-for-sale [Line Items]
Amortized Cost		$ 14,717	$ 17,365
Gross Unrealized Gains		1,093	1,179
Gross Unrealized Losses		(871)	(1,652)
Securities, at fair value(1)(2)		$ 14,939	$ 16,892
Long | Interest only securities | Weighted Average
Securities, Available-for-sale [Line Items]
Weighted Average Coupon		1.29%	1.36%
Weighted Average Yield		10.68%	10.11%
Weighted average life		5 years 3 months 25 days	5 years 3 months 25 days
Long | Non-Agency RMBS
Securities, Available-for-sale [Line Items]
Current Principal		$ 393,738	$ 388,304
Unamortized Premium (Discount)		(135,108)	(130,167)
Amortized Cost		258,630	258,137
Gross Unrealized Gains		5,943	5,228
Gross Unrealized Losses		(29,365)	(24,475)
Securities, at fair value(1)(2)		$ 235,208	$ 238,890
Long | Non-Agency RMBS | Weighted Average
Securities, Available-for-sale [Line Items]
Weighted Average Coupon		4.61%	4.33%
Weighted Average Yield		8.53%	7.29%
Weighted average life		6 years 6 months 7 days	5 years 8 months 26 days
Long | CMBS
Securities, Available-for-sale [Line Items]
Current Principal		$ 38,996	$ 38,996
Unamortized Premium (Discount)		(17,527)	(17,722)
Amortized Cost		21,469	21,274
Gross Unrealized Gains		337	287
Gross Unrealized Losses		(8,681)	(6,992)
Securities, at fair value(1)(2)		$ 13,125	$ 14,569
Long | CMBS | Weighted Average
Securities, Available-for-sale [Line Items]
Weighted Average Coupon		2.54%	2.54%
Weighted Average Yield		8.32%	8.43%
Weighted average life		8 years 6 months 18 days	8 years 3 months 29 days
Long | Non-Agency IOs
Securities, Available-for-sale [Line Items]
Amortized Cost		$ 29,771	$ 24,588
Gross Unrealized Gains		5,214	3,566
Gross Unrealized Losses		(1,952)	(1,182)
Securities, at fair value(1)(2)		$ 33,033	$ 26,972
Long | Non-Agency IOs | Weighted Average
Securities, Available-for-sale [Line Items]
Weighted Average Coupon		0.18%	0.18%
Weighted Average Yield		14.87%	14.21%
Weighted average life		6 years 11 months 19 days	7 years 7 months 24 days
Long | CLOs
Securities, Available-for-sale [Line Items]
Amortized Cost		$ 46,990	$ 45,240
Gross Unrealized Gains		2,922	3,217
Gross Unrealized Losses		(17,744)	(17,396)
Securities, at fair value(1)(2)		$ 32,168	$ 31,061
Long | CLOs | Weighted Average
Securities, Available-for-sale [Line Items]
Weighted Average Coupon		2.09%	2.16%
Weighted Average Yield		8.72%	9.37%
Weighted average life		2 years 11 months 1 day	3 years 21 days
Long | Asset-backed securities, backed by consumer loans
Securities, Available-for-sale [Line Items]
Current Principal		$ 118,319	$ 115,604
Unamortized Premium (Discount)		(35,170)	(28,282)
Amortized Cost		83,149	87,322
Gross Unrealized Gains		341	278
Gross Unrealized Losses		(11,290)	(13,956)
Securities, at fair value(1)(2)		$ 72,200	$ 73,644
Long | Asset-backed securities, backed by consumer loans | Weighted Average
Securities, Available-for-sale [Line Items]
Weighted Average Coupon		12.00%	11.87%
Weighted Average Yield		13.67%	13.42%
Weighted average life		1 year 2 months 26 days	1 year 2 months 15 days
Long | Corporate debt securities
Securities, Available-for-sale [Line Items]
Current Principal		$ 31,394	$ 30,872
Unamortized Premium (Discount)		(23,316)	(23,337)
Amortized Cost		8,078	7,535
Gross Unrealized Gains		819	551
Gross Unrealized Losses		(550)	(553)
Securities, at fair value(1)(2)		$ 8,347	$ 7,533
Long | Corporate debt securities | Weighted Average
Securities, Available-for-sale [Line Items]
Weighted Average Coupon		0.00%	0.00%
Weighted Average Yield		0.00%	0.00%
Weighted average life		2 years 6 months 18 days	2 years 1 month 28 days
Long | Corporate equity securities
Securities, Available-for-sale [Line Items]
Amortized Cost		$ 9,258	$ 9,799
Gross Unrealized Gains		3,141	2,941
Gross Unrealized Losses		(1,297)	(1,629)
Securities, at fair value(1)(2)		11,102	11,111
Long | U.S. Treasury securities
Securities, Available-for-sale [Line Items]
Current Principal		130,153	88,699
Unamortized Premium (Discount)		219	640
Amortized Cost		130,372	89,339
Gross Unrealized Gains		1,540	0
Gross Unrealized Losses		(660)	(1,917)
Securities, at fair value(1)(2)		$ 131,252	$ 87,422
Long | U.S. Treasury securities | Weighted Average
Securities, Available-for-sale [Line Items]
Weighted Average Coupon		3.73%	3.58%
Weighted Average Yield		3.67%	3.46%
Weighted average life		6 years 5 months 4 days	7 years 21 days
Short
Securities, Available-for-sale [Line Items]
Current Principal		$ (168,008)	$ (226,170)
Unamortized Premium (Discount)		778	4,624
Investment Sold, Not yet Purchased, Sale Proceeds		(167,230)	(221,546)
Gross Unrealized Gains		8,954	13,074
Gross Unrealized Losses		(26)	(731)
Securities sold short, at fair value		$ (158,302)	$ (209,203)
Short | Weighted Average
Securities, Available-for-sale [Line Items]
Weighted Average Coupon		1.78%	1.94%
Weighted Average Yield		1.98%	2.29%
Weighted average life		3 years 6 months	4 years 9 months 25 days
Short | Corporate debt securities
Securities, Available-for-sale [Line Items]
Current Principal			$ (200,850)
Unamortized Premium (Discount)			6,132
Investment Sold, Not yet Purchased, Sale Proceeds			(194,718)
Gross Unrealized Gains			10,025
Gross Unrealized Losses			(731)
Securities sold short, at fair value			$ (185,424)
Short | Corporate debt securities | Weighted Average
Securities, Available-for-sale [Line Items]
Weighted Average Coupon			2.18%
Weighted Average Yield			2.60%
Weighted average life			5 years 1 month 28 days
Short | U.S. Treasury securities
Securities, Available-for-sale [Line Items]
Current Principal		$ (141,340)
Unamortized Premium (Discount)		1,803
Investment Sold, Not yet Purchased, Sale Proceeds		(139,537)
Gross Unrealized Gains		6,501
Gross Unrealized Losses		(26)
Securities sold short, at fair value		$ (133,062)
Short | U.S. Treasury securities | Weighted Average
Securities, Available-for-sale [Line Items]
Weighted Average Coupon		2.11%
Weighted Average Yield		2.34%
Weighted average life		3 years 9 months 14 days
Short | European sovereign bonds
Securities, Available-for-sale [Line Items]
Current Principal		$ (26,668)	$ (25,320)
Unamortized Premium (Discount)		(1,025)	(1,508)
Investment Sold, Not yet Purchased, Sale Proceeds		(27,693)	(26,828)
Gross Unrealized Gains		2,453	3,049
Gross Unrealized Losses		0	0
Securities sold short, at fair value		$ (25,240)	$ (23,779)
Short | European sovereign bonds | Weighted Average
Securities, Available-for-sale [Line Items]
Weighted Average Coupon		0.01%	0.01%
Weighted Average Yield		0.15%	0.04%
Weighted average life		1 year 11 months 4 days	2 years 2 months 1 day

[1] Ellington Financial Inc.'s Condensed Consolidated Balance Sheets include assets and liabilities of variable interest entities it has consolidated. See Note 11 for additional details on Ellington Financial Inc.'s consolidated variable interest entities.

[2] Includes assets pledged as collateral to counterparties. See Note 13 for additional details on the Company's borrowings and related collateral.