Fair Value Measurements - Valuation Assumptions (Details)	Jun. 30, 2020	Dec. 31, 2019
Discount rate | In-house valuation of collateral, External pricing model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan measured for impairment, measurement input (percent)	0.50	0.25
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)	0.9055	0.9265
Mortgage servicing rights | Discount rate | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Servicing rights, measurement input (percent)	0.0775
Mortgage servicing rights | Discount rate | Minimum | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Servicing rights, measurement input (percent)		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)		0.0866
Mortgage servicing rights | Constant prepayment rate | Minimum | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Servicing rights, measurement input (percent)	0.0810	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)	0.1456	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