Capitalized Mortgage Servicing Rights (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Capitalized Mortgage Servicing Rights
Balance at beginning of the year	$ 379,974
Balance at end of the year	422,734	$ 379,974
MSRs
Capitalized Mortgage Servicing Rights
Balance at beginning of the year	379,974	286,420
Additions	134,116	159,533
Amortization	(58,615)	(49,222)
Write-downs and payoffs	(32,741)	(16,757)
Balance at end of the year	422,734	379,974
Prepayment fees collected	38,200	$ 12,800
Valuation allowance	0
Expected amortization of capitalized MSRs balances
2022	58,814
2023	55,777
2024	53,179
2025	50,610
2026	46,582
Thereafter	157,772
Total	$ 422,734
MSRs | Weighted average
Capitalized Mortgage Servicing Rights
Estimated life remaining	8 years 6 months	8 years 7 months 6 days
Originated MSRs
Capitalized Mortgage Servicing Rights
Balance at beginning of the year	$ 336,466	$ 221,901
Additions	134,116	159,533
Amortization	(47,845)	(34,186)
Write-downs and payoffs	(27,164)	(10,782)
Balance at end of the year	395,573	336,466
Acquired MSRs
Capitalized Mortgage Servicing Rights
Balance at beginning of the year	43,508	64,519
Amortization	(10,770)	(15,036)
Write-downs and payoffs	(5,577)	(5,975)
Balance at end of the year	$ 27,161	$ 43,508