Short-Term Debt - Maturities of Outstanding Advances Under Repurchase Agreements (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2022 USD ($)
Mortgage loans sold under agreement to repurchase
Unpaid principal balance	$ 2,446,014
Weighted-average maturity (in months)	4 months
Within 30 days
Mortgage loans sold under agreement to repurchase
Unpaid principal balance	$ 430,925
Over 30 to 90 days
Mortgage loans sold under agreement to repurchase
Unpaid principal balance	1,491,071
Over 90 to 180 days
Mortgage loans sold under agreement to repurchase
Unpaid principal balance	41,509
Over 180 days to one year
Mortgage loans sold under agreement to repurchase
Unpaid principal balance	382,509
Over one year to two year
Mortgage loans sold under agreement to repurchase
Unpaid principal balance	$ 100,000