Summary of Significant Accounting Policies - Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Bank-Owned Life Insurance
Bank owned life insurance	$ 177.0	$ 167.6
Bank owned life insurance income	$ 7.8	$ 1.5
Building
Non-accrual Loans and Leases
Premise and equipment, useful life	39 years
Minimum
Non-accrual Loans and Leases
Number of days interest and principal are past due for loans and leases to be placed on non-accrual status	90 days
Number of days interest and principal for third party consumer first mortgage lien are past due to be placed on non-accrual status	90 days
Sustained repayment performance period through which loans and leases are reported as non-accrual loans and leases	6 months
Sustained repayment performance period through which income on loans and leases is recognized on cash basis	9 months
Minimum | Property, Plant and Equipment, Other Types
Non-accrual Loans and Leases
Premise and equipment, useful life	3 years
Maximum
Non-accrual Loans and Leases
Sustained repayment performance period through which income on loans and leases is recognized on cash basis	12 months
Number of days delinquent through which income on loans and leases is recognized on cash basis	60 days
Maximum | Property, Plant and Equipment, Other Types
Non-accrual Loans and Leases
Premise and equipment, useful life	15 years
Interest rate swap | Derivatives designated as hedges
Derivative Instruments
Derivative liability, notional amount	$ 150.0
Forward foreign exchange contracts | Net investment hedges
Derivative Instruments
Maximum remaining maturity of foreign currency derivatives	35 days
Forward foreign exchange contracts | Not Designated as Hedges
Derivative Instruments
Maximum remaining maturity of foreign currency derivatives	35 days
Interest rate contracts | Not Designated as Hedges | Minimum
Derivative Instruments
Derivative term	2 years
Interest rate contracts | Not Designated as Hedges | Maximum
Derivative Instruments
Derivative term	15 years
Interest rate lock commitments | Not Designated as Hedges | Maximum
Derivative Instruments
Derivative, remaining maturity	10 months