Fair Values of Assets and Liabilities - Narrative (Details)	12 Months Ended
	Dec. 31, 2024 USD ($) $ / shares	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	$ 4,141,482,000	$ 3,502,915,000
Loans held-for-investment	158,795,000	155,261,000
MSRs	203,788,000	192,456,000	$ 230,225,000	$ 147,571,000
Individually assessed loans - foreclosure probable and collateral-dependent	119,325,000	91,153,000
Estimate of Fair Value Measurement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	4,141,482,000	3,502,915,000
Remaining contractual principal balance outstanding, mortgage loans held-for-sale	335,900,000	291,700,000
Remaining contractual principal balance outstanding, mortgage loans held-for-investment	157,800,000	156,900,000
Non-performing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held-for-sale classified as nonaccrual	4,000,000	649,000
Mortgage loans held-for-sale classified greater than 90 days past due and still accruing	$ 59,300,000	26,600,000
Weighted Average | Loans held-for-investment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Life of loans	6 years 1 month 6 days
Appraisal adjustment - cost of sale | Other real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate owned, measurement input	0.10
Measured at fair value on a recurring basis:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held-for-sale	$ 331,261,000	292,722,000
Loans held-for-investment	158,795,000	155,261,000
MSRs	203,788,000	192,456,000
Derivative assets	200,027,000	275,726,000
Measured at fair value on a non-recurring basis:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Individually assessed loans - foreclosure probable and collateral-dependent	119,325,000
Other real estate owned	23,116,000
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Individually assessed loans - foreclosure probable and collateral-dependent	119,300,000
Level 3 | Portion at Other than Fair Value Measurement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Individually assessed loans - foreclosure probable and collateral-dependent	0
Level 3 | Measured at fair value on a recurring basis:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held-for-sale	60,399,000	26,835,000
Loans held-for-investment	34,896,000	60,670,000
MSRs	203,788,000	192,456,000
Derivative assets	$ 1,950,000	4,510,000
Level 3 | Measured at fair value on a recurring basis: | Discount rate | Weighted Average | Discounted cash flows
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
MSRs, measurement input	0.1095
Level 3 | Measured at fair value on a recurring basis: | Discount rate | Weighted Average | Mortgage loans held-for-sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	0.0661
Level 3 | Measured at fair value on a recurring basis: | Discount rate | Weighted Average | Loans held-for-investment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	0.0661
Level 3 | Measured at fair value on a recurring basis: | Discount rate | Weighted Average | Mortgage Servicing Rights
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	0.1095
Level 3 | Measured at fair value on a recurring basis: | Discount rate | Minimum | Discounted cash flows
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
MSRs, measurement input	0.06
Level 3 | Measured at fair value on a recurring basis: | Discount rate | Minimum | Mortgage Servicing Rights
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	0.06
Level 3 | Measured at fair value on a recurring basis: | Discount rate | Maximum | Discounted cash flows
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
MSRs, measurement input	0.18
Level 3 | Measured at fair value on a recurring basis: | Discount rate | Maximum | Mortgage Servicing Rights
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	0.18
Level 3 | Measured at fair value on a recurring basis: | Credit discount | Weighted Average | Mortgage loans held-for-sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	0.0069
Level 3 | Measured at fair value on a recurring basis: | Credit discount | Weighted Average | Loans held-for-investment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	0.0117
Level 3 | Measured at fair value on a recurring basis: | Credit discount | Minimum | Mortgage loans held-for-sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	0
Level 3 | Measured at fair value on a recurring basis: | Credit discount | Minimum | Loans held-for-investment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	0
Level 3 | Measured at fair value on a recurring basis: | Credit discount | Maximum | Mortgage loans held-for-sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	0.20
Level 3 | Measured at fair value on a recurring basis: | Credit discount | Maximum | Loans held-for-investment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	0.39
Level 3 | Measured at fair value on a recurring basis: | Constant prepayment rate (CPR) | Weighted Average | Discounted cash flows
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
MSRs, measurement input	0.0829
Level 3 | Measured at fair value on a recurring basis: | Constant prepayment rate (CPR) | Weighted Average | Loans held-for-investment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	0.0829
Level 3 | Measured at fair value on a recurring basis: | Constant prepayment rate (CPR) | Weighted Average | Mortgage Servicing Rights
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	0.0829
Level 3 | Measured at fair value on a recurring basis: | Constant prepayment rate (CPR) | Minimum | Discounted cash flows
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
MSRs, measurement input	0.04
Level 3 | Measured at fair value on a recurring basis: | Constant prepayment rate (CPR) | Minimum | Mortgage Servicing Rights
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	0.04
Level 3 | Measured at fair value on a recurring basis: | Constant prepayment rate (CPR) | Maximum | Discounted cash flows
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
MSRs, measurement input	0.90
Level 3 | Measured at fair value on a recurring basis: | Constant prepayment rate (CPR) | Maximum | Mortgage Servicing Rights
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	0.90
Level 3 | Measured at fair value on a recurring basis: | Cost of servicing | Weighted Average | Discounted cash flows
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
MSRs, measurement input	76
Level 3 | Measured at fair value on a recurring basis: | Cost of servicing | Minimum | Discounted cash flows
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
MSRs, measurement input | $ / shares	70
Level 3 | Measured at fair value on a recurring basis: | Cost of servicing | Maximum | Discounted cash flows
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
MSRs, measurement input | $ / shares	200
Level 3 | Measured at fair value on a recurring basis: | Cost of servicing - delinquent | Weighted Average | Discounted cash flows
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
MSRs, measurement input	378
Level 3 | Measured at fair value on a recurring basis: | Cost of servicing - delinquent | Minimum | Discounted cash flows
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
MSRs, measurement input | $ / shares	200
Level 3 | Measured at fair value on a recurring basis: | Cost of servicing - delinquent | Maximum | Discounted cash flows
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
MSRs, measurement input | $ / shares	1,000
Level 3 | Measured at fair value on a recurring basis: | Pull-through rate | Weighted Average | Discounted cash flows
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, measurement input	0.8252
Level 3 | Measured at fair value on a recurring basis: | Pull-through rate | Minimum | Discounted cash flows
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, measurement input	0.01
Level 3 | Measured at fair value on a recurring basis: | Pull-through rate | Maximum | Discounted cash flows
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, measurement input	1
Level 3 | Measured at fair value on a non-recurring basis:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Individually assessed loans - foreclosure probable and collateral-dependent	$ 119,325,000
Other real estate owned	23,116,000
Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	184,593,000	140,958,000
Municipal securities | Measured at fair value on a recurring basis:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	184,593,000	140,958,000
Municipal securities | Level 3 | Measured at fair value on a recurring basis:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	$ 121,607,000	$ 86,237,000