CONSOLIDATED BALANCE SHEETS (Unaudited) CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Amortized cost of available-for-sale investment securities,	$ 507,477	$ 548,640
Allowance for credit losses on loans	$ 8,916	$ 9,326
Preferred stock, liquidation preference (in dollars per share)	$ 1,000	$ 1,000
Preferred stock, authorized (in shares)	10,000,000	10,000,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, authorized (in shares)	80,000,000	80,000,000
Common stock, issued (in shares)	12,212,190	12,143,815
Common stock, outstanding (in shares)	12,212,190	12,143,815
Common stock, par value (in dollars per share)	$ 0	$ 0