Income Taxes - Reconciliation of Expected Tax Benefit with Pretax Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Tax rate applied to income before income taxes	$ 18,381	$ 27,720	$ 15,431
Increase (decrease) resulting from the effects of:
Tax law change	0	8,552	0
Nondeductible acquisition costs	207	657	217
Tax exempt interest on loans, obligations of states and political subdivisions and bank owned life insurance	(667)	(1,445)	(1,215)
State income taxes	(874)	(1,007)	(726)
Tax credit investments	(33)	(165)	(55)
Stock compensation	(918)	(1,027)	(731)
Other	0	173	(105)
Federal tax provision	16,096	33,458	12,816
State tax provision	4,163	2,878	2,073
Total income tax provision	$ 20,259	$ 36,336	$ 14,889