Allowance for Credit Losses - Credit Quality Indicators by Class of Residential Real Estate and Consumer Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases, net of unearned income and deferred costs and fees	$ 5,096,778	$ 5,260,327
Residential real estate | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	1,395	1,440
One year before current fiscal year	1,246	2,782
Two years before current fiscal year	3,173	1,052
Three years before current fiscal year	1,719	2,120
Four years before current fiscal year	1,728	916
Prior	4,042	1,612
Revolving Loans Amortized Cost Basis	167,403	190,861
Revolving Loans Converted to Term	4,919	44
Total loans and leases, net of unearned income and deferred costs and fees	185,625	200,827
Residential real estate | Mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	233,145	305,476
One year before current fiscal year	289,745	193,801
Two years before current fiscal year	169,136	123,660
Three years before current fiscal year	105,265	156,405
Four years before current fiscal year	132,900	179,553
Prior	325,809	262,861
Revolving Loans Amortized Cost Basis	13,088	11,787
Revolving Loans Converted to Term	917	1,617
Total loans and leases, net of unearned income and deferred costs and fees	1,270,005	1,235,160
Residential real estate | Performing | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	1,395	1,440
One year before current fiscal year	1,246	2,764
Two years before current fiscal year	3,157	1,052
Three years before current fiscal year	1,719	2,120
Four years before current fiscal year	1,728	722
Prior	3,446	1,106
Revolving Loans Amortized Cost Basis	165,588	188,614
Revolving Loans Converted to Term	4,919	44
Total loans and leases, net of unearned income and deferred costs and fees	183,198	197,862
Residential real estate | Performing | Mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	233,145	305,476
One year before current fiscal year	289,745	193,543
Two years before current fiscal year	168,894	123,205
Three years before current fiscal year	104,697	155,699
Four years before current fiscal year	132,204	178,149
Prior	317,803	255,556
Revolving Loans Amortized Cost Basis	13,062	11,735
Revolving Loans Converted to Term	917	1,617
Total loans and leases, net of unearned income and deferred costs and fees	1,260,467	1,224,980
Residential real estate | Nonperforming | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	0	0
One year before current fiscal year	0	18
Two years before current fiscal year	16	0
Three years before current fiscal year	0	0
Four years before current fiscal year	0	194
Prior	596	506
Revolving Loans Amortized Cost Basis	1,815	2,247
Revolving Loans Converted to Term	0	0
Total loans and leases, net of unearned income and deferred costs and fees	2,427	2,965
Residential real estate | Nonperforming | Mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	0	0
One year before current fiscal year	0	258
Two years before current fiscal year	242	455
Three years before current fiscal year	568	706
Four years before current fiscal year	696	1,404
Prior	8,006	7,305
Revolving Loans Amortized Cost Basis	26	52
Revolving Loans Converted to Term	0	0
Total loans and leases, net of unearned income and deferred costs and fees	9,538	10,180
Consumer and other | Direct
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	17,310	14,845
One year before current fiscal year	11,574	11,201
Two years before current fiscal year	10,227	8,178
Three years before current fiscal year	6,025	6,644
Four years before current fiscal year	5,191	2,854
Prior	11,265	10,842
Revolving Loans Amortized Cost Basis	5,102	6,835
Revolving Loans Converted to Term	0	0
Total loans and leases, net of unearned income and deferred costs and fees	66,694	61,399
Consumer and other | Indirect
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	1,484	1,424
One year before current fiscal year	965	1,945
Two years before current fiscal year	445	3,371
Three years before current fiscal year	2,085	1,135
Four years before current fiscal year	486	418
Prior	130	108
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total loans and leases, net of unearned income and deferred costs and fees	5,595	8,401
Consumer and other | Performing | Direct
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	17,310	14,840
One year before current fiscal year	11,569	11,127
Two years before current fiscal year	10,163	8,011
Three years before current fiscal year	5,962	6,632
Four years before current fiscal year	5,180	2,854
Prior	11,265	10,840
Revolving Loans Amortized Cost Basis	5,099	6,835
Revolving Loans Converted to Term	0	0
Total loans and leases, net of unearned income and deferred costs and fees	66,548	61,139
Consumer and other | Performing | Indirect
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	1,484	1,424
One year before current fiscal year	965	1,878
Two years before current fiscal year	308	3,327
Three years before current fiscal year	1,987	1,128
Four years before current fiscal year	484	382
Prior	102	93
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total loans and leases, net of unearned income and deferred costs and fees	5,330	8,232
Consumer and other | Nonperforming | Direct
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	0	5
One year before current fiscal year	5	74
Two years before current fiscal year	64	167
Three years before current fiscal year	63	12
Four years before current fiscal year	11	0
Prior	0	2
Revolving Loans Amortized Cost Basis	3	0
Revolving Loans Converted to Term	0	0
Total loans and leases, net of unearned income and deferred costs and fees	146	260
Consumer and other | Nonperforming | Indirect
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current fiscal year	0	0
One year before current fiscal year	0	67
Two years before current fiscal year	137	44
Three years before current fiscal year	98	7
Four years before current fiscal year	2	36
Prior	28	15
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total loans and leases, net of unearned income and deferred costs and fees	$ 265	$ 169