Allowance for Loan Losses and Credit Quality of Loans, Troubled Debt Restructuring (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019 USD ($) Contract	Sep. 30, 2018 USD ($) Contract	Sep. 30, 2019 USD ($) Contract	Sep. 30, 2018 USD ($) Contract
Troubled Debt Restructured Loans [Abstract]
Number of contracts | Contract	3	8	31	25
Pre-modification outstanding recorded investment	$ 216	$ 90	$ 1,947	$ 918
Post-modification outstanding recorded investment	$ 240	$ 89	$ 2,011	$ 918
Number of contracts | Contract	19	22	45	54
Recorded Investment	$ 914	$ 1,214	$ 2,213	$ 3,237
Commercial Loans [Member]
Troubled Debt Restructured Loans [Abstract]
Number of contracts | Contract			3	3
Pre-modification outstanding recorded investment			$ 453	$ 369
Post-modification outstanding recorded investment			$ 453	$ 371
Number of contracts | Contract			0	2
Recorded Investment			$ 0	$ 258
Commercial Loans [Member] | C&I [Member]
Troubled Debt Restructured Loans [Abstract]
Number of contracts | Contract			1	0
Pre-modification outstanding recorded investment			$ 65	$ 0
Post-modification outstanding recorded investment			$ 65	$ 0
Commercial Loans [Member] | Business Banking [Member]
Troubled Debt Restructured Loans [Abstract]
Number of contracts | Contract			2	3
Pre-modification outstanding recorded investment			$ 388	$ 369
Post-modification outstanding recorded investment			$ 388	$ 371
Number of contracts | Contract			0	2
Recorded Investment			$ 0	$ 258
Consumer Loans [Member]
Troubled Debt Restructured Loans [Abstract]
Number of contracts | Contract	1	8	18	17
Pre-modification outstanding recorded investment	$ 30	$ 90	$ 552	$ 226
Post-modification outstanding recorded investment	$ 37	$ 89	$ 568	$ 224
Number of contracts | Contract	10	17	26	35
Recorded Investment	$ 342	$ 816	$ 1,126	$ 1,740
Consumer Loans [Member] | Dealer Finance [Member]
Troubled Debt Restructured Loans [Abstract]
Number of contracts | Contract	0	8	9	15
Pre-modification outstanding recorded investment	$ 0	$ 90	$ 134	$ 185
Post-modification outstanding recorded investment	$ 0	$ 89	$ 134	$ 183
Number of contracts | Contract	1	0	2	0
Recorded Investment	$ 10	$ 0	$ 17	$ 0
Consumer Loans [Member] | Direct [Member]
Troubled Debt Restructured Loans [Abstract]
Number of contracts | Contract	1	0	9	2
Pre-modification outstanding recorded investment	$ 30	$ 0	$ 418	$ 41
Post-modification outstanding recorded investment	$ 37	$ 0	$ 434	$ 41
Number of contracts | Contract	9	17	24	35
Recorded Investment	$ 332	$ 816	$ 1,109	$ 1,740
Residential Real Estate [Member]
Troubled Debt Restructured Loans [Abstract]
Number of contracts | Contract	2	0	10	5
Pre-modification outstanding recorded investment	$ 186	$ 0	$ 942	$ 323
Post-modification outstanding recorded investment	$ 203	$ 0	$ 990	$ 323
Number of contracts | Contract	9	5	19	17
Recorded Investment	$ 572	$ 398	$ 1,087	$ 1,239