Fair Value Measurements - Valuation Assumptions (Details)	Mar. 31, 2020	Dec. 31, 2019
Discount rate | In-house valuation of collateral, External pricing model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input (percent)		0.25
Discount rate | Minimum | In-house valuation of collateral, External pricing model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input (percent)	0.25
Discount rate | Maximum | In-house valuation of collateral, External pricing model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input (percent)	0.75
Pull through rate | In-house valuation of collateral, External pricing model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Interest rate lock commitment, measurement input (percent)	0.8876	0.9265
Mortgage servicing rights | Discount rate | Minimum | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Servicing rights, measurement input (percent)	0.0858	0.0851
Mortgage servicing rights | Discount rate | Maximum | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Servicing rights, measurement input (percent)	0.0886	0.0866
Mortgage servicing rights | Constant prepayment rate | Minimum | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Servicing rights, measurement input (percent)	0.0931	0.0911
Mortgage servicing rights | Constant prepayment rate | Maximum | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Servicing rights, measurement input (percent)	0.1160	0.1067
Commercial servicing rights | Discount rate | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Servicing rights, measurement input (percent)	0.1170	0.1170
Commercial servicing rights | Constant prepayment rate | Minimum | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Servicing rights, measurement input (percent)	0.0764	0.0764
Commercial servicing rights | Constant prepayment rate | Maximum | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Servicing rights, measurement input (percent)	0.1567	0.1567