Mortgage Servicing Rights - Information of MSRs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Transfers and Servicing [Abstract]
Unpaid principal balance	$ 8,728,629	$ 7,322,671	$ 4,871,155
Weighted-average prepayment speed (CPR)	10.56%	15.05%	11.48%
Estimated impact of a 10% increase	$ (3,875)	$ (4,001)	$ (2,469)
Estimated impact of a 20% increase	$ (7,464)	$ (7,674)	$ (4,774)
Discount rate	9.82%	9.86%	9.69%
Estimated impact of a 100bp increase	$ (4,153)	$ (2,144)	$ (2,027)
Estimated impact of a 200bp increase	$ (8,119)	$ (4,144)	$ (3,908)
Weighted-average coupon interest rate	3.29%	3.58%	4.04%
Weighted-average servicing fee (basis points)	0.3037%	0.2994%	0.292%
Weighted-average remaining maturity (in years)	6 years 8 months 8 days	5 years 1 month 20 days	6 years 4 months 6 days