Loans (Changes in the Allowance for Credit Losses) (Details) - USD ($) $ in Thousands		3 Months Ended	6 Months Ended
Dec. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance		$ 43,356	$ 33,327	$ 40,076	$ 33,914
Allowance for loan losses, Charge-offs		(3,723)	(3,173)	(15,755)	(6,625)
Allowance for loan losses, Recoveries		2,937	1,926	4,826	3,598
Allowance for loan losses, Provision (credit)		3,746	2,354	17,169	3,547
Allowance for loan losses, Ending balance	$ 40,076	46,316	34,434	46,316	34,434
Beginning balance, prior to adoption of ASC 326	30,482	46,316		46,316
Impact of adopting ASC 326	9,594
Loans, Ending balance	3,179,465	3,451,529	3,110,064	3,451,529	3,110,064
Allowance for loan losses, Individually Evaluated for impairment			8,042		8,042
Allowance for loan losses, Collectively Evaluated for impairment			3,102,022		3,102,022
Allowance for loan losses, Individually Evaluated for impairment			3,107		3,107
Allowance for loan losses, Collectively Evaluated for impairment			31,327		31,327
Commercial Business [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance		10,223	12,167	11,112	14,312
Allowance for loan losses, Charge-offs		(25)	(138)	(8,266)	(268)
Allowance for loan losses, Recoveries		1,483	128	1,541	231
Allowance for loan losses, Provision (credit)		718	(440)	8,012	(2,558)
Allowance for loan losses, Ending balance	11,112	12,399	11,717	12,399	11,717
Beginning balance, prior to adoption of ASC 326	11,358
Impact of adopting ASC 326	(246)
Loans, Ending balance	571,222	824,818	594,121	824,818	594,121
Allowance for loan losses, Individually Evaluated for impairment			768		768
Allowance for loan losses, Collectively Evaluated for impairment			593,353		593,353
Allowance for loan losses, Individually Evaluated for impairment			110		110
Allowance for loan losses, Collectively Evaluated for impairment			11,607		11,607
Commercial Mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance		15,154	6,316	12,991	5,219
Allowance for loan losses, Charge-offs		(1,072)	(3)	(1,072)	(3)
Allowance for loan losses, Recoveries		0	0	0	17
Allowance for loan losses, Provision (credit)		1,584	2,477	3,747	3,557
Allowance for loan losses, Ending balance	12,991	15,666	8,790	15,666	8,790
Beginning balance, prior to adoption of ASC 326	5,681
Impact of adopting ASC 326	7,310
Loans, Ending balance	1,108,315	1,142,359	1,011,925	1,142,359	1,011,925
Allowance for loan losses, Individually Evaluated for impairment			7,274		7,274
Allowance for loan losses, Collectively Evaluated for impairment			1,004,651		1,004,651
Allowance for loan losses, Individually Evaluated for impairment			2,997		2,997
Allowance for loan losses, Collectively Evaluated for impairment			5,793		5,793
Residential Real Estate Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance		6,170	1,265	4,349	1,112
Allowance for loan losses, Charge-offs		(2)	(87)	(100)	(118)
Allowance for loan losses, Recoveries		8	11	18	17
Allowance for loan losses, Provision (credit)		(407)	28	1,502	206
Allowance for loan losses, Ending balance	4,349	5,769	1,217	5,769	1,217
Beginning balance, prior to adoption of ASC 326	1,059
Impact of adopting ASC 326	3,290
Loans, Ending balance	560,717	572,562	535,873	572,562	535,873
Allowance for loan losses, Individually Evaluated for impairment			0		0
Allowance for loan losses, Collectively Evaluated for impairment			535,873		535,873
Allowance for loan losses, Individually Evaluated for impairment			0		0
Allowance for loan losses, Collectively Evaluated for impairment			1,217		1,217
Residential Real Estate Lines [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance		899	173	725	210
Allowance for loan losses, Charge-offs		0	(2)	0	(2)
Allowance for loan losses, Recoveries		0	3	3	5
Allowance for loan losses, Provision (credit)		40	(29)	211	(68)
Allowance for loan losses, Ending balance	725	939	145	939	145
Beginning balance, prior to adoption of ASC 326	118
Impact of adopting ASC 326	607
Loans, Ending balance	101,048	94,285	104,937	94,285	104,937
Allowance for loan losses, Individually Evaluated for impairment			0		0
Allowance for loan losses, Collectively Evaluated for impairment			104,937		104,937
Allowance for loan losses, Individually Evaluated for impairment			0		0
Allowance for loan losses, Collectively Evaluated for impairment			145		145
Consumer Indirect [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance		10,645	13,025	10,618	12,572
Allowance for loan losses, Charge-offs		(2,554)	(2,700)	(5,978)	(5,682)
Allowance for loan losses, Recoveries		1,379	1,678	3,047	3,102
Allowance for loan losses, Provision (credit)		1,752	154	3,535	2,165
Allowance for loan losses, Ending balance	10,618	11,222	12,157	11,222	12,157
Beginning balance, prior to adoption of ASC 326	11,852
Impact of adopting ASC 326	(1,234)
Loans, Ending balance	822,179	801,434	846,829	801,434	846,829
Allowance for loan losses, Individually Evaluated for impairment			0		0
Allowance for loan losses, Collectively Evaluated for impairment			846,829		846,829
Allowance for loan losses, Individually Evaluated for impairment			0		0
Allowance for loan losses, Collectively Evaluated for impairment			12,157		12,157
Other Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning balance		265	381	281	489
Allowance for loan losses, Charge-offs		(70)	(243)	(339)	(552)
Allowance for loan losses, Recoveries		67	106	217	226
Allowance for loan losses, Provision (credit)		59	164	162	245
Allowance for loan losses, Ending balance	281	321	408	321	408
Beginning balance, prior to adoption of ASC 326	414
Impact of adopting ASC 326	(133)
Loans, Ending balance	$ 15,984	$ 16,071	16,379	$ 16,071	16,379
Allowance for loan losses, Individually Evaluated for impairment			0		0
Allowance for loan losses, Collectively Evaluated for impairment			16,379		16,379
Allowance for loan losses, Individually Evaluated for impairment			0		0
Allowance for loan losses, Collectively Evaluated for impairment			$ 408		$ 408

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

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount of expense related loan transactions, lease transactions, credit loss from transactions other than loan and lease transactions, and other loss based on assessment of uncollectability from the counterparty to reduce the account to their net realizable value.

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