v3.26.3
Fair Value of Assets and Liabilities - Schedule of Valuation Techniques and Significant Unobservable Inputs Used to Measure Both Recurring and Non Recurring (Details)
Sep. 30, 2026
USD ($)
year
$ / shares
Jun. 30, 2026
USD ($)
Dec. 31, 2025
USD ($)
Sep. 30, 2025
USD ($)
Jun. 30, 2025
USD ($)
Dec. 31, 2024
USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Available-for-sale securities $ 7,569,498,000   $ 6,236,263,000 $ 5,274,124,000    
Loans held-for-investment 145,750,000     129,593,000    
MSRs 238,485,000 $ 201,903,000 195,023,000 190,938,000 $ 193,061,000 $ 203,788,000
Individually assessed loans - foreclosure probable and collateral-dependent 125,970,000     124,966,000    
Municipal securities            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Available-for-sale securities 164,324,000   162,166,000 194,244,000    
Measured at fair value on a recurring basis:            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Mortgage loans held-for-sale 307,748,000   340,745,000 333,883,000    
Loans held-for-investment 145,750,000   151,590,000 129,593,000    
MSRs 238,485,000   195,023,000 190,938,000    
Derivative assets 205,591,000   179,667,000 208,957,000    
Measured at fair value on a recurring basis: | Municipal securities            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Available-for-sale securities 164,324,000   162,166,000 194,244,000    
Measured at fair value on a non-recurring basis:            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Individually assessed loans - foreclosure probable and collateral-dependent 125,970,000          
Other real estate owned 16,404,000          
Level 3            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Individually assessed loans - foreclosure probable and collateral-dependent 126,000,000.0          
Level 3 | Measured at fair value on a recurring basis:            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Mortgage loans held-for-sale 52,726,000   53,814,000 54,726,000    
Loans held-for-investment 50,523,000   56,200,000 49,220,000    
MSRs 238,485,000   195,023,000 190,938,000    
Derivative assets $ 816,000   3,416,000 7,149,000    
Level 3 | Measured at fair value on a recurring basis: | Discount rate | Discounted cash flows            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Mortgage loans held-for-sale, measurement input 0.0641          
Level 3 | Measured at fair value on a recurring basis: | Discount rate | Discounted cash flows | Minimum            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Loans held-for-investment, measurement input 0.0641          
MSRs, measurement input 0.0900          
Level 3 | Measured at fair value on a recurring basis: | Discount rate | Discounted cash flows | Maximum            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Loans held-for-investment, measurement input 0.0738          
MSRs, measurement input 0.1300          
Level 3 | Measured at fair value on a recurring basis: | Discount rate | Discounted cash flows | Weighted Average            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Mortgage loans held-for-sale, measurement input 0.0641          
Loans held-for-investment, measurement input 0.0646          
MSRs, measurement input 0.0982          
Level 3 | Measured at fair value on a recurring basis: | Credit discount | Discounted cash flows | Minimum            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Mortgage loans held-for-sale, measurement input 0.0000          
Loans held-for-investment, measurement input 0.0000          
Level 3 | Measured at fair value on a recurring basis: | Credit discount | Discounted cash flows | Maximum            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Mortgage loans held-for-sale, measurement input 0.2973          
Loans held-for-investment, measurement input 0.3798          
Level 3 | Measured at fair value on a recurring basis: | Credit discount | Discounted cash flows | Weighted Average            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Mortgage loans held-for-sale, measurement input 0.0066          
Loans held-for-investment, measurement input 0.0178          
Level 3 | Measured at fair value on a recurring basis: | Constant prepayment rate (CPR) - current loans | Discounted cash flows            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Loans held-for-investment, measurement input 0.0756          
Level 3 | Measured at fair value on a recurring basis: | Constant prepayment rate (CPR) - current loans | Discounted cash flows | Minimum            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
MSRs, measurement input 0.0578          
Level 3 | Measured at fair value on a recurring basis: | Constant prepayment rate (CPR) - current loans | Discounted cash flows | Maximum            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
MSRs, measurement input 1.0000          
Level 3 | Measured at fair value on a recurring basis: | Constant prepayment rate (CPR) - current loans | Discounted cash flows | Weighted Average            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Loans held-for-investment, measurement input 0.0756          
MSRs, measurement input 0.0756          
Level 3 | Measured at fair value on a recurring basis: | Average life - delinquent loans (in years) | Discounted cash flows | Minimum            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Loans held-for-investment, measurement input | year 1.2          
Level 3 | Measured at fair value on a recurring basis: | Average life - delinquent loans (in years) | Discounted cash flows | Maximum            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Loans held-for-investment, measurement input | year 12.3          
Level 3 | Measured at fair value on a recurring basis: | Average life - delinquent loans (in years) | Discounted cash flows | Weighted Average            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Loans held-for-investment, measurement input | year 5.3          
Level 3 | Measured at fair value on a recurring basis: | Cost of servicing | Discounted cash flows | Minimum            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
MSRs, measurement input | $ / shares 70          
Level 3 | Measured at fair value on a recurring basis: | Cost of servicing | Discounted cash flows | Maximum            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
MSRs, measurement input | $ / shares 95          
Level 3 | Measured at fair value on a recurring basis: | Cost of servicing | Discounted cash flows | Weighted Average            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
MSRs, measurement input 76          
Level 3 | Measured at fair value on a recurring basis: | Cost of servicing - delinquent | Discounted cash flows | Minimum            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
MSRs, measurement input | $ / shares 200          
Level 3 | Measured at fair value on a recurring basis: | Cost of servicing - delinquent | Discounted cash flows | Maximum            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
MSRs, measurement input | $ / shares 1,000          
Level 3 | Measured at fair value on a recurring basis: | Cost of servicing - delinquent | Discounted cash flows | Weighted Average            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
MSRs, measurement input 375          
Level 3 | Measured at fair value on a recurring basis: | Pull-through rate | Discounted cash flows | Minimum            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Derivatives, measurement input 0.1955          
Level 3 | Measured at fair value on a recurring basis: | Pull-through rate | Discounted cash flows | Maximum            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Derivatives, measurement input 1          
Level 3 | Measured at fair value on a recurring basis: | Pull-through rate | Discounted cash flows | Weighted Average            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Derivatives, measurement input 0.8789          
Level 3 | Measured at fair value on a recurring basis: | Municipal securities            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Available-for-sale securities $ 119,676,000   $ 99,603,000 $ 129,794,000    
Level 3 | Measured at fair value on a non-recurring basis:            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Individually assessed loans - foreclosure probable and collateral-dependent 125,970,000          
Other real estate owned $ 16,404,000          
Level 3 | Measured at fair value on a non-recurring basis: | Appraisal adjustment - cost of sale | Appraisal value            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Impaired loans - collateral based, measurement input 0.1000          
Other real estate owned, measurement input 0.1000          
Level 3 | Measured at fair value on a non-recurring basis: | Appraisal adjustment - cost of sale | Appraisal value | Weighted Average            
Fair Value Measurement Inputs and Valuation Techniques [Line Items]            
Impaired loans - collateral based, measurement input 0.1000          
Other real estate owned, measurement input 0.1000