Loans (Changes in the Allowance for Credit Losses) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	$ 30,482	$ 33,914	$ 34,672
Allowance for loan losses, Charge-offs	(21,625)	(17,811)	(15,734)
Allowance for loan losses, Recoveries	7,810	6,335	6,042
Allowance for loan losses, Provision (credit)	26,159	8,044	8,934
Allowance for loan losses, Ending balance	52,420	30,482	33,914
Allowance for loan losses, Individually Evaluated for impairment		693	206
Allowance for loan losses, Collectively Evaluated for impairment		29,789	33,708
Allowance for loan losses, Individually Evaluated for impairment		4,323	3,078
Allowance for loan losses, Collectively Evaluated for impairment		3,175,142	3,041,242
Loans, Ending balance	3,557,908	3,179,465	3,044,320
Cumulative-Effect Adjustment [Member] \| ASU 2016-13 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	9,594
Allowance for loan losses, Ending balance		9,594
Adjusted Balance [Member] \| ASU 2016-13 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	40,076
Allowance for loan losses, Ending balance		40,076
Commercial Business [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	11,358	14,312	15,668
Allowance for loan losses, Charge-offs	(9,093)	(2,481)	(2,319)
Allowance for loan losses, Recoveries	1,709	492	509
Allowance for loan losses, Provision (credit)	9,852	(965)	454
Allowance for loan losses, Ending balance	13,580	11,358	14,312
Allowance for loan losses, Individually Evaluated for impairment		214	205
Allowance for loan losses, Collectively Evaluated for impairment		11,144	14,107
Allowance for loan losses, Individually Evaluated for impairment		1,177	1,044
Allowance for loan losses, Collectively Evaluated for impairment		570,045	555,996
Loans, Ending balance	798,409	571,222	557,040
Commercial Business [Member] \| Cumulative-Effect Adjustment [Member] \| ASU 2016-13 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	(246)
Allowance for loan losses, Ending balance		(246)
Commercial Business [Member] \| Adjusted Balance [Member] \| ASU 2016-13 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	11,112
Allowance for loan losses, Ending balance		11,112
Commercial Mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	5,681	5,219	3,696
Allowance for loan losses, Charge-offs	(1,792)	(2,997)	(1,020)
Allowance for loan losses, Recoveries	37	17	13
Allowance for loan losses, Provision (credit)	10,527	3,442	2,530
Allowance for loan losses, Ending balance	21,763	5,681	5,219
Allowance for loan losses, Individually Evaluated for impairment		479	1
Allowance for loan losses, Collectively Evaluated for impairment		5,202	5,218
Allowance for loan losses, Individually Evaluated for impairment		3,146	2,034
Allowance for loan losses, Collectively Evaluated for impairment		1,105,169	958,231
Loans, Ending balance	1,256,525	1,108,315	960,265
Commercial Mortgage [Member] \| Cumulative-Effect Adjustment [Member] \| ASU 2016-13 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	7,310
Allowance for loan losses, Ending balance		7,310
Commercial Mortgage [Member] \| Adjusted Balance [Member] \| ASU 2016-13 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	12,991
Allowance for loan losses, Ending balance		12,991
Residential Real Estate Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	1,059	1,112	1,322
Allowance for loan losses, Charge-offs	(100)	(340)	(95)
Allowance for loan losses, Recoveries	28	43	159
Allowance for loan losses, Provision (credit)	(353)	244	(274)
Allowance for loan losses, Ending balance	3,924	1,059	1,112
Allowance for loan losses, Collectively Evaluated for impairment		1,059	1,112
Allowance for loan losses, Collectively Evaluated for impairment		560,717	514,981
Loans, Ending balance	586,537	560,717	514,981
Residential Real Estate Loans [Member] \| Cumulative-Effect Adjustment [Member] \| ASU 2016-13 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	3,290
Allowance for loan losses, Ending balance		3,290
Residential Real Estate Loans [Member] \| Adjusted Balance [Member] \| ASU 2016-13 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	4,349
Allowance for loan losses, Ending balance		4,349
Residential Real Estate Lines [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	118	210	180
Allowance for loan losses, Charge-offs		(13)	(142)
Allowance for loan losses, Recoveries	3	6	20
Allowance for loan losses, Provision (credit)	(54)	(85)	152
Allowance for loan losses, Ending balance	674	118	210
Allowance for loan losses, Collectively Evaluated for impairment		118	210
Allowance for loan losses, Collectively Evaluated for impairment		101,048	106,712
Loans, Ending balance	86,708	101,048	106,712
Residential Real Estate Lines [Member] \| Cumulative-Effect Adjustment [Member] \| ASU 2016-13 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	607
Allowance for loan losses, Ending balance		607
Residential Real Estate Lines [Member] \| Adjusted Balance [Member] \| ASU 2016-13 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	725
Allowance for loan losses, Ending balance		725
Consumer Indirect [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	11,852	12,572	13,415
Allowance for loan losses, Charge-offs	(9,959)	(10,810)	(10,850)
Allowance for loan losses, Recoveries	5,681	5,390	5,024
Allowance for loan losses, Provision (credit)	5,825	4,700	4,983
Allowance for loan losses, Ending balance	12,165	11,852	12,572
Allowance for loan losses, Collectively Evaluated for impairment		11,852	12,572
Allowance for loan losses, Collectively Evaluated for impairment		822,179	888,732
Loans, Ending balance	812,816	822,179	888,732
Consumer Indirect [Member] \| Cumulative-Effect Adjustment [Member] \| ASU 2016-13 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	(1,234)
Allowance for loan losses, Ending balance		(1,234)
Consumer Indirect [Member] \| Adjusted Balance [Member] \| ASU 2016-13 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	10,618
Allowance for loan losses, Ending balance		10,618
Other Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	414	489	391
Allowance for loan losses, Charge-offs	(681)	(1,170)	(1,308)
Allowance for loan losses, Recoveries	352	387	317
Allowance for loan losses, Provision (credit)	362	708	1,089
Allowance for loan losses, Ending balance	314	414	489
Allowance for loan losses, Collectively Evaluated for impairment		414	489
Allowance for loan losses, Collectively Evaluated for impairment		15,984	16,590
Loans, Ending balance	16,913	15,984	$ 16,590
Other Consumer [Member] \| Cumulative-Effect Adjustment [Member] \| ASU 2016-13 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	(133)
Allowance for loan losses, Ending balance		(133)
Other Consumer [Member] \| Adjusted Balance [Member] \| ASU 2016-13 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	$ 281
Allowance for loan losses, Ending balance		$ 281

Financing receivable allowance for loan losses, provision (credit).

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Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of increase in allowance for credit loss on financing receivable from recovery.

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Amount of writeoff of financing receivable, charged against allowance for credit loss.

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The balance of financing receivables that were collectively evaluated for impairment.

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Amount, before allowance for credit loss, of financing receivable.

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