Commitments, Guarantees and Contingent Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fixed Rate, Commitments to make loans	$ 53,556	$ 42,458
Fixed Rate, Unused lines of credit	9,799	6,245
Fixed Rate, Standby letters of credit	0	0
Fixed Rate, Total	63,355	48,703
Variable Rate, Commitments to make loans	174,401	161,778
Variable Rate, Unused lines of credit	468,512	408,831
Variable Rate, Standby letters of credit	7,882	7,605
Variable Rate, Total	$ 650,795	$ 578,214