Significant Accounting Policies (Details) $ in Thousands		6 Months Ended
	Nov. 18, 2016 USD ($) Branch	Jun. 30, 2018 USD ($) Component Category Factor	Dec. 31, 2017 USD ($)	Jun. 30, 2017 USD ($)
Acquisition [Abstract]
Total assets | $		$ 3,097,823	$ 3,075,452	$ 3,012,599
Investment Securities [Abstract]
Number of components into which amount of impairment is split | Component		2
Loans & Leases [Abstract]
Consecutive months of payments to demonstrate sustained period of performance		6 months
Allowance for Credit Losses [Abstract]
Number of primary components of overall allowance for credit losses | Component		3
Number of categories into which risk ratings are grouped | Category		5
Minimum [Member]
Loans & Leases [Abstract]
Period after which loans are placed on non accrual status		90 days
Buildings [Member] | Minimum [Member]
Premises and Equipment [Abstract]
Estimated useful lives		30 years
Buildings [Member] | Maximum [Member]
Premises and Equipment [Abstract]
Estimated useful lives		40 years
Furniture and Equipment [Member] | Minimum [Member]
Premises and Equipment [Abstract]
Estimated useful lives		3 years
Furniture and Equipment [Member] | Maximum [Member]
Premises and Equipment [Abstract]
Estimated useful lives		7 years
Leasehold Improvements [Member] | Minimum [Member]
Premises and Equipment [Abstract]
Estimated useful lives		5 years
Leasehold Improvements [Member] | Maximum [Member]
Premises and Equipment [Abstract]
Estimated useful lives		10 years
Agricultural Real Estate [Member]
Allowance for Credit Losses [Abstract]
Number of risk factors on loans | Factor		2
Agricultural [Member]
Allowance for Credit Losses [Abstract]
Number of risk factors on loans | Factor		2
Delta National Bancorp [Member]
Acquisition [Abstract]
Total assets | $	$ 112,000
Number of branches | Branch	4