Loans - Average Recorded Investment and Interest Income on Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Accounts, Notes, Loans and Financing Receivable
Average Recorded Investment	$ 176,525	$ 155,776	$ 173,157	$ 158,980
Interest Income Recognized	1,401	1,162	3,941	3,722
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Average Recorded Investment	114,233	87,414	112,308	88,376
Interest Income Recognized	763	422	1,777	1,348
Commercial real estate
Accounts, Notes, Loans and Financing Receivable
Average Recorded Investment	49,962	51,796	47,403	54,804
Interest Income Recognized	551	571	1,817	1,789
Commercial real estate \| Commercial real estate
Accounts, Notes, Loans and Financing Receivable
Average Recorded Investment	49,608	50,809	46,894	52,993
Interest Income Recognized	551	556	1,817	1,735
Commercial real estate \| Construction
Accounts, Notes, Loans and Financing Receivable
Average Recorded Investment	354	987	509	1,811
Interest Income Recognized	0	15	0	54
Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Average Recorded Investment	11,592	14,112	12,574	13,707
Interest Income Recognized	76	152	315	502
Consumer loans
Accounts, Notes, Loans and Financing Receivable
Average Recorded Investment	738	2,454	872	2,093
Interest Income Recognized	11	17	32	83
Consumer loans \| Home equity
Accounts, Notes, Loans and Financing Receivable
Average Recorded Investment	738	2,454	872	2,093
Interest Income Recognized	$ 11	$ 17	$ 32	$ 83

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.

No definition available.

+ Details

Name:	us-gaap_AccountsNotesAndLoansReceivableLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5212-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5258-111524

+ Details

Name:	us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of interest income recognized on a cash-basis method of accounting that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

+ References

+ Details

Name:	us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_RealEstateLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConstructionLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_HomeEquityLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: