CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Securities held to maturity, fair value (in dollars)	$ 65,133	$ 53,249
Preferred stock, no par value	$ 0	$ 0
Preferred stock, shares authorized	100,000	100,000
Class A Common Stock
Common Stock, no par value	$ 0	$ 0
Common Stock, shares authorized	30,000,000	30,000,000
Common Stock, issued	18,606,338	18,614,961
Common Stock, outstanding	18,606,338	18,614,961
Class B Common Stock
Common Stock, no par value	$ 0	$ 0
Common Stock, shares authorized	5,000,000	5,000,000
Common Stock, issued	2,242,624	2,245,011
Common Stock, outstanding	2,242,624	2,245,011