(Schedule of Reverse Repurchase Agreements by Maturity) (Details) $ in Thousands		3 Months Ended	12 Months Ended
		Mar. 31, 2020 USD ($) counterparty	Dec. 31, 2019 USD ($) counterparty
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	[1]	$ 2,034,225	$ 2,445,300
Number of Counterparties with Outstanding Reverse Repurchase Agreements | counterparty		28	28
Total secured borrowings		$ 2,800,000	$ 3,200,000
Agency RMBS
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		1,287,030	1,864,473
Agency RMBS | 30 Days or Less
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		353,826	511,996
Agency RMBS | 31-60 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		750,285	744,387
Agency RMBS | 61-90 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		182,557	594,738
Agency RMBS | 91-120 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		362	10,270
Agency RMBS | 181-360 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		0	3,082
U.S. Treasury securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		1,654	0
U.S. Treasury securities | 30 Days or Less
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		1,654	0
Credit
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		745,541	580,827
Credit | 30 Days or Less
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		37,567	16,549
Credit | 31-60 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		160,313	104,491
Credit | 61-90 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		161,312	138,837
Credit | 91-120 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		104,950	0
Credit | 151-180 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		0	7,460
Credit | 181-360 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		211,624	31,498
Credit | More Than 360 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		22,725	186,661
Credit | Total Credit Assets
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		$ 47,050	$ 95,331
Minimum
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate		(0.15%)	0.15%
Repurchase agreements, remaining days to maturity		1 day	2 days
Maximum
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate		6.99%	5.20%
Repurchase agreements, remaining days to maturity		791 days	882 days
Weighted Average
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate		2.11%	2.37%
Repurchase agreements, remaining days to maturity		80 days	91 days
Weighted Average | Agency RMBS
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate		1.64%	1.98%
Repurchase agreements, remaining days to maturity		42 days	48 days
Weighted Average | Agency RMBS | 30 Days or Less
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate		1.65%	2.08%
Repurchase agreements, remaining days to maturity		16 days	17 days
Weighted Average | Agency RMBS | 31-60 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate		1.79%	1.93%
Repurchase agreements, remaining days to maturity		46 days	47 days
Weighted Average | Agency RMBS | 61-90 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate		1.01%	1.96%
Repurchase agreements, remaining days to maturity		75 days	76 days
Weighted Average | Agency RMBS | 91-120 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate		2.49%	2.24%
Repurchase agreements, remaining days to maturity		113 days	93 days
Weighted Average | Agency RMBS | 181-360 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate		0.00%	2.67%
Repurchase agreements, remaining days to maturity		0 days	171 days
Weighted Average | U.S. Treasury securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate		(0.15%)	0.00%
Repurchase agreements, remaining days to maturity		1 day	0 days
Weighted Average | U.S. Treasury securities | 30 Days or Less
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate		(0.15%)	0.00%
Repurchase agreements, remaining days to maturity		1 day	0 days
Weighted Average | Credit
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate		2.93%	3.61%
Repurchase agreements, remaining days to maturity		147 days	229 days
Weighted Average | Credit | 30 Days or Less
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate		3.04%	3.38%
Repurchase agreements, remaining days to maturity		20 days	25 days
Weighted Average | Credit | 31-60 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate		2.81%	3.14%
Repurchase agreements, remaining days to maturity		44 days	48 days
Weighted Average | Credit | 61-90 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate		2.61%	3.03%
Repurchase agreements, remaining days to maturity		74 days	73 days
Weighted Average | Credit | 91-120 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate		3.46%	0.00%
Repurchase agreements, remaining days to maturity		92 days	0 days
Weighted Average | Credit | 151-180 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate		0.00%	3.89%
Repurchase agreements, remaining days to maturity		0 days	123 days
Weighted Average | Credit | 181-360 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate		2.70%	3.87%
Repurchase agreements, remaining days to maturity		171 days	173 days
Weighted Average | Credit | More Than 360 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate		3.39%	3.80%
Repurchase agreements, remaining days to maturity		284 days	250 days
Weighted Average | Credit | Total Credit Assets
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate		3.95%	4.52%
Repurchase agreements, remaining days to maturity		791 days	678 days

[1] Ellington Financial Inc.'s Condensed Consolidated Balance Sheet includes assets and liabilities of variable interest entities it has consolidated. See Note 9 for additional details on Ellington Financial Inc.'s consolidated variable interest entities.