Revenue Revenue from contracts with customers (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Commission and fees from sale of insurance policies	$ 3,033	$ 3,189
Fees related to third party insurance administration services	169	119
Performance-based insurance commissions	1,419	1,347
Interchange electronic banking income	2,443	2,264
Promotional and usage electronic banking income	544	521
Ongoing maintenance fees for deposit accounts	752	675
Transactional-based fees for deposit accounts	1,589	1,445
Transactional-based fees included in other non-interest income	171	281
Revenue from Contract with Customer, Excluding Assessed Tax	13,378	13,025
Fiduciary and Trust [Member]
Revenue from Contract with Customer, Including Assessed Tax	3,112	3,068
Interest Rate Swap [Member] | transaction fee [Member]
Revenue from Contract with Customer, Including Assessed Tax	146	116
Transferred over Time [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	10,053	9,836
Transferred at Point in Time [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 3,325	$ 3,189