Commitments and Contingent Liabilities - Summary of Contract or Notional Amount of Outstanding Loan and Lease Commitments (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Commitments And Contingencies Liabilities [Line Items]
Fixed Rate	$ 44,923	$ 38,791
Variable Rate	398,432	337,063
Commitments to Extend Credit
Commitments And Contingencies Liabilities [Line Items]
Fixed Rate	44,068	37,731
Variable Rate	394,622	332,928
Standby Letters of Credit
Commitments And Contingencies Liabilities [Line Items]
Fixed Rate	855	1,060
Variable Rate	$ 3,810	$ 4,135