Loans - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Troubled Debt Restructuring Outstanding	$ 14,800,000		$ 15,600,000
Loans and Leases Receivable, Impaired, Troubled Debt, Interest Income	400,000	$ 400,000
Loans and Leases Receivable, Impaired, Interest Income Recognized, Change in Present Value Attributable to Passage of Time	88,000	61,000
Impaired Financing Receivable, Average Recorded Investment	31,100,000	$ 30,400,000
PCI Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Deferred Costs, Noncurrent	$ 13,900,000		$ 12,900,000