Repurchase Agreements - Remaining Term to Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Weighted Average Rate	2.90%	0.23%
WAVG Original Term to Maturity	83	198
Repurchase agreements	$ 3,009,269	$ 2,849,916
Less than 30 days
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Weighted Average Rate	2.86%	0.42%
WAVG Original Term to Maturity	63	123
Repurchase agreements	$ 963,976	$ 602,994
30 to 90 days
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Weighted Average Rate	2.82%	0.14%
WAVG Original Term to Maturity	75	166
Repurchase agreements	$ 1,603,853	$ 763,302
91 to 180 days
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Weighted Average Rate	3.31%	0.15%
WAVG Original Term to Maturity	154	198
Repurchase agreements	$ 441,440	$ 1,075,324
181 days to 1 year
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Weighted Average Rate	0.00%	0.30%
WAVG Original Term to Maturity	0	366
Repurchase agreements	$ 0	$ 408,296