Fair Values of Assets and Liabilities - Valuation Assumption Ranges for Derivative Commitments (Details)	Mar. 31, 2024
Minimum | Expected loan close rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative commitments measurement inputs	0.10
Minimum | Inherent MSR value (basis points per loan)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative commitments measurement inputs	0.0055
Maximum | Expected loan close rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative commitments measurement inputs	1
Maximum | Inherent MSR value (basis points per loan)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative commitments measurement inputs	0.0184
Weighted Average | Expected loan close rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative commitments measurement inputs	0.76
Weighted Average | Inherent MSR value (basis points per loan)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative commitments measurement inputs	0.0103