Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation Of Revenue [Line Items]
TOTAL NONINTEREST INCOME	$ 6,478	$ 6,058	$ 18,794	$ 18,000
Service Charges on Deposit Accounts
Disaggregation Of Revenue [Line Items]
Noninterest income	1,151	1,077	3,139	3,017
Debit Card and EFT Fees
Disaggregation Of Revenue [Line Items]
Noninterest income	814	770	2,490	2,259
Trust Fees
Disaggregation Of Revenue [Line Items]
Noninterest income	1,827	1,608	5,374	4,809
Insurance Agency Commissions
Disaggregation Of Revenue [Line Items]
Noninterest income	567	531	1,979	1,877
Retirement Plan Consulting Fees
Disaggregation Of Revenue [Line Items]
Noninterest income	470	480	1,314	1,392
Investment Commissions
Disaggregation Of Revenue [Line Items]
Noninterest income	273	184	844	659
Operating Segments
Disaggregation Of Revenue [Line Items]
TOTAL NONINTEREST INCOME	6,478	6,058	18,794	18,000
Operating Segments | Trust Segment
Disaggregation Of Revenue [Line Items]
TOTAL NONINTEREST INCOME	1,827	1,608	5,374	4,809
Operating Segments | Bank Segment
Disaggregation Of Revenue [Line Items]
TOTAL NONINTEREST INCOME	4,181	3,970	12,106	11,799
Operating Segments | Retirement Consulting Segment
Disaggregation Of Revenue [Line Items]
TOTAL NONINTEREST INCOME	470	480	1,314	1,392
Operating Segments | Service Charges on Deposit Accounts
Disaggregation Of Revenue [Line Items]
Noninterest income	1,151	1,077	3,139	3,017
Operating Segments | Service Charges on Deposit Accounts | Trust Segment
Disaggregation Of Revenue [Line Items]
Noninterest income	0	0	0	0
Operating Segments | Service Charges on Deposit Accounts | Bank Segment
Disaggregation Of Revenue [Line Items]
Noninterest income	1,151	1,077	3,139	3,017
Operating Segments | Service Charges on Deposit Accounts | Retirement Consulting Segment
Disaggregation Of Revenue [Line Items]
Noninterest income	0	0	0	0
Operating Segments | Debit Card and EFT Fees
Disaggregation Of Revenue [Line Items]
Noninterest income	814	770	2,490	2,259
Operating Segments | Debit Card and EFT Fees | Trust Segment
Disaggregation Of Revenue [Line Items]
Noninterest income	0	0	0	0
Operating Segments | Debit Card and EFT Fees | Bank Segment
Disaggregation Of Revenue [Line Items]
Noninterest income	814	770	2,490	2,259
Operating Segments | Debit Card and EFT Fees | Retirement Consulting Segment
Disaggregation Of Revenue [Line Items]
Noninterest income	0	0	0	0
Operating Segments | Trust Fees
Disaggregation Of Revenue [Line Items]
Noninterest income	1,827	1,608	5,374	4,809
Operating Segments | Trust Fees | Trust Segment
Disaggregation Of Revenue [Line Items]
Noninterest income	1,827	1,608	5,374	4,809
Operating Segments | Trust Fees | Bank Segment
Disaggregation Of Revenue [Line Items]
Noninterest income	0	0	0	0
Operating Segments | Trust Fees | Retirement Consulting Segment
Disaggregation Of Revenue [Line Items]
Noninterest income	0	0	0	0
Operating Segments | Insurance Agency Commissions
Disaggregation Of Revenue [Line Items]
Noninterest income	567	531	1,979	1,877
Operating Segments | Insurance Agency Commissions | Trust Segment
Disaggregation Of Revenue [Line Items]
Noninterest income	0	0	0	0
Operating Segments | Insurance Agency Commissions | Bank Segment
Disaggregation Of Revenue [Line Items]
Noninterest income	567	531	1,979	1,877
Operating Segments | Insurance Agency Commissions | Retirement Consulting Segment
Disaggregation Of Revenue [Line Items]
Noninterest income	0	0	0	0
Operating Segments | Retirement Plan Consulting Fees
Disaggregation Of Revenue [Line Items]
Noninterest income	470	480	1,314	1,392
Operating Segments | Retirement Plan Consulting Fees | Trust Segment
Disaggregation Of Revenue [Line Items]
Noninterest income	0	0	0	0
Operating Segments | Retirement Plan Consulting Fees | Bank Segment
Disaggregation Of Revenue [Line Items]
Noninterest income	0	0	0	0
Operating Segments | Retirement Plan Consulting Fees | Retirement Consulting Segment
Disaggregation Of Revenue [Line Items]
Noninterest income	470	480	1,314	1,392
Operating Segments | Investment Commissions
Disaggregation Of Revenue [Line Items]
Noninterest income	273	184	844	659
Operating Segments | Investment Commissions | Trust Segment
Disaggregation Of Revenue [Line Items]
Noninterest income	0	0	0	0
Operating Segments | Investment Commissions | Bank Segment
Disaggregation Of Revenue [Line Items]
Noninterest income	273	184	844	659
Operating Segments | Investment Commissions | Retirement Consulting Segment
Disaggregation Of Revenue [Line Items]
Noninterest income	0	0	0	0
Operating Segments | Other
Disaggregation Of Revenue [Line Items]
Noninterest income	1,376	1,408	3,654	3,987
Operating Segments | Other | Trust Segment
Disaggregation Of Revenue [Line Items]
Noninterest income	0	0	0	0
Operating Segments | Other | Bank Segment
Disaggregation Of Revenue [Line Items]
Noninterest income	1,376	1,408	3,654	3,987
Operating Segments | Other | Retirement Consulting Segment
Disaggregation Of Revenue [Line Items]
Noninterest income	$ 0	$ 0	$ 0	$ 0