Repurchase Agreements - Remaining Term to Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Balance	$ 2,849,916	$ 2,437,163
Weighted Average Rate	0.23%	0.34%
WAVG Original Term to Maturity	198	44
Less than 30 days
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Balance	$ 602,994	$ 1,416,608
Weighted Average Rate	0.42%	0.37%
WAVG Original Term to Maturity	123	53
30 to 90 days
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Balance	$ 763,302	$ 845,394
Weighted Average Rate	0.14%	0.31%
WAVG Original Term to Maturity	166	35
91 to 180 days
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Balance	$ 1,075,324	$ 175,161
Weighted Average Rate	0.15%	0.22%
WAVG Original Term to Maturity	198	13
180 days to 1 year
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Balance	$ 408,296
Weighted Average Rate	0.30%
WAVG Original Term to Maturity	366