Securities - Additional Information (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2017 USD ($) security	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($) security
Schedule Of Available-For-Sale And Held-To-Maturity [Line Items]
Available for sale securities carrying value pledged to secure public deposits	$ 47,100		$ 34,300
Gross gains on sales of securities available for sale	146	$ 167
Gross losses on sales of securities available for sale (less than in 2016)	39	$ 1
Fair value of available-for-sale securities	53,274		56,987
Unrealized loss of available-for-sale securities	$ 1,168		1,600
Number of securities with unrealized losses, held-to-maturity | security	0
Fair value of held-to-maturity securities			789
Unrealized loss of held-to-maturity securities			$ 2
U.S. Government Agencies [Member]
Schedule Of Available-For-Sale And Held-To-Maturity [Line Items]
Number of securities with unrealized losses, available-for-sale | security	8		5
Fair value of available-for-sale securities	$ 13,266		$ 7,078
Unrealized loss of available-for-sale securities	$ 94		$ 57
State And Political Subdivisions [Member]
Schedule Of Available-For-Sale And Held-To-Maturity [Line Items]
Number of securities with unrealized losses, available-for-sale | security	17		31
Fair value of available-for-sale securities	$ 14,930		$ 23,989
Unrealized loss of available-for-sale securities	$ 524		$ 770
Number of securities with unrealized losses from state and political subdivisions maturity minimum number of years	10 years
Number of securities with unrealized losses, held-to-maturity | security			2
Fair value of held-to-maturity securities			$ 789
Unrealized loss of held-to-maturity securities			$ 2
U.S. Government-Sponsored Enterprises [Member]
Schedule Of Available-For-Sale And Held-To-Maturity [Line Items]
Number of securities with unrealized losses, available-for-sale | security	17		16
Fair value of available-for-sale securities	$ 25,078		$ 23,938
Unrealized loss of available-for-sale securities	$ 550		$ 755
Corporate Debt [Member]
Schedule Of Available-For-Sale And Held-To-Maturity [Line Items]
Number of securities with unrealized losses, available-for-sale | security	0		1
Fair value of available-for-sale securities	$ 0		$ 1,982
Unrealized loss of available-for-sale securities	$ 0		$ 18