Summary of Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2017
Summary of Significant Accounting Policies [Abstract]
Minimum number of days past due for nonaccrual loan status	90 days
Period of sustained repayment performance for nonperforming TDRs to be returned to performing status	6 months
Standby letters of credit expiration period	1 year