(Schedule of Reverse Repurchase Agreements by Maturity) (Details) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2019 USD ($) counterparty		Dec. 31, 2018 USD ($) counterparty
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	$ 1,715,506	[1]	$ 1,498,849
Number of Counterparties with Outstanding Reverse Repurchase Agreements | counterparty	24		23
Total secured borrowings	$ 2,293,000		$ 1,911,000
Agency RMBS
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	1,240,726		917,262
Agency RMBS | 30 Days or Less
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	283,477		245,956
Agency RMBS | 31-60 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	441,099		415,379
Agency RMBS | 61-90 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	386,366		255,421
Agency RMBS | 91-120 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	102,410		506
Agency RMBS | 151-180 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	27,374
U.S. Treasury securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	687		273
U.S. Treasury securities | 30 Days or Less
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	687		273
Credit
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	474,093
Credit | 30 Days or Less
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	142		30,426
Credit | 31-60 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	107,370		189,937
Credit | 61-90 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	80,450		93,202
Credit | 91-120 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	100,032		26,222
Credit | 151-180 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	612		9,491
Credit | 181-360 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	9,118		91,730
Credit | More Than 360 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	89,488		140,306
Credit | Total Credit Assets
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	$ 86,881		$ 581,314
Minimum
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate	0.24%		0.23%
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	5.60%		6.07%
Repurchase agreements, remaining days to maturity	874 days		871 days
Weighted Average
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate	3.06%		3.13%
Repurchase agreements, remaining days to maturity	109 days		122 days
Weighted Average | Agency RMBS
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate	2.61%		2.59%
Repurchase agreements, remaining days to maturity	57 days		47 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	2.64%		2.46%
Repurchase agreements, remaining days to maturity	19 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	2.62%		2.58%
Repurchase agreements, remaining days to maturity	48 days		46 days
Weighted Average | Agency RMBS | 61-90 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate	2.57%		2.74%
Repurchase agreements, remaining days to maturity	76 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	2.60%		3.31%
Repurchase agreements, remaining days to maturity	103 days		91 days
Weighted Average | Agency RMBS | 151-180 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate	2.59%
Repurchase agreements, remaining days to maturity	137 days
Weighted Average | U.S. Treasury securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate	3.10%		3.10%
Repurchase agreements, remaining days to maturity	1 day		2 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	3.10%		3.10%
Repurchase agreements, remaining days to maturity	1 day		2 days
Weighted Average | Credit
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate	4.26%
Repurchase agreements, remaining days to maturity	246 days
Weighted Average | Credit | 30 Days or Less
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate	4.57%		2.55%
Repurchase agreements, remaining days to maturity	1 day		22 days
Weighted Average | Credit | 31-60 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate	3.52%		3.32%
Repurchase agreements, remaining days to maturity	50 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	3.60%		3.21%
Repurchase agreements, remaining days to maturity	77 days		74 days
Weighted Average | Credit | 91-120 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate	4.56%		4.60%
Repurchase agreements, remaining days to maturity	117 days		123 days
Weighted Average | Credit | 151-180 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate	3.92%		4.64%
Repurchase agreements, remaining days to maturity	150 days		166 days
Weighted Average | Credit | 181-360 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate	4.32%		4.54%
Repurchase agreements, remaining days to maturity	168 days		316 days
Weighted Average | Credit | More Than 360 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate	4.60%		5.15%
Repurchase agreements, remaining days to maturity	205 days		636 days
Weighted Average | Credit | Total Credit Assets
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase Agreements Interest Rate	5.09%		3.98%
Repurchase agreements, remaining days to maturity	848 days		240 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.