Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Jan. 01, 2018	Dec. 31, 2017
Cumulative Effect on Retained Earnings, Net of Tax	$ 3,100
Insurance income	4,655	$ 4,102
Accrued expenses and other liabilities	37,977			$ 39,254
Retained earnings (b)	143,297			$ 134,362
Other non-interest income (a)	1,331	412
Deferred Revenue	4,309		$ 4,700
Deferred Revenue, Additions	1,824
Deferred Revenue, Revenue Recognized	(2,215)
Commission and fees from sale of insurance policies	3,189
Fees related to third party insurance administration services	119
Performance-based insurance commissions	1,347
Trust and investment income	3,068	2,682
Interchange electronic banking income	2,264
Promotional and usage electronic banking income	521
Ongoing maintenance fees for deposit accounts	675
Transactional-based fees for deposit accounts	1,445
Commercial loan swap fees	116	$ 268
Transactional-based fees included in other non-interest income	281
Revenue from Contract with Customer, Excluding Assessed Tax	13,025
Accounting Standards Update 2014-09 [Member]
Cumulative Effect on Retained Earnings, Net of Tax	3,100
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Insurance income	(391)
Accrued expenses and other liabilities	2,746
Retained earnings (b)	(2,746)
Other non-interest income (a)	400
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Insurance income	4,264
Accrued expenses and other liabilities	35,231
Retained earnings (b)	146,043
Transferred at Point in Time [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	3,189
Transferred over Time [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 9,836