Allowance for Credit Losses - Recorded Investment in Consumer Loan Classes by Performing and Nonperforming Status (Details) - Consumer $ in Thousands	Dec. 31, 2019 USD ($)
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases receivables, recorded investment	$ 1,624,356
Percentage of Total	100.00%
Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases receivables, recorded investment	$ 1,614,158
Percentage of Total	99.40%
Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases receivables, recorded investment	$ 10,198
Percentage of Total	0.60%
Residential Mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases receivables, recorded investment	$ 998,585
Percentage of Total	100.00%
Residential Mortgage | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases receivables, recorded investment	$ 991,066
Percentage of Total	99.20%
Residential Mortgage | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases receivables, recorded investment	$ 7,519
Percentage of Total	0.80%
Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases receivables, recorded investment	$ 538,348
Percentage of Total	100.00%
Home equity | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases receivables, recorded investment	$ 535,709
Percentage of Total	99.50%
Home equity | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases receivables, recorded investment	$ 2,639
Percentage of Total	0.50%
Installment and other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases receivables, recorded investment	$ 79,033
Percentage of Total	100.00%
Installment and other consumer | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases receivables, recorded investment	$ 78,993
Percentage of Total	99.90%
Installment and other consumer | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases receivables, recorded investment	$ 40
Percentage of Total	0.10%
Consumer construction
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases receivables, recorded investment	$ 8,390
Percentage of Total	100.00%
Consumer construction | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases receivables, recorded investment	$ 8,390
Percentage of Total	100.00%
Consumer construction | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases receivables, recorded investment	$ 0
Percentage of Total	0.00%