Credit Quality Assessment (Additional Information) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable Troubled Debt Restructurings Restructured Accruing	$ 1,900	$ 1,600
Other real estate owned	2,742	3,195
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other real estate owned	1,900
Restructured Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable Troubled Debt Restructurings Specific Allowance	500	100
Financing Receivable Troubled Debt Restructurings Restructured Accruing	4,500	5,500
Financing Receivable Troubled Debt Restructurings Restructured Non Accruing	6,900	6,100
Financing Receivable Troubled Debt Restructurings Balance	11,400	11,600
Additional Financing Receivable Troubled Debt Restructurings Restructured	$ 100	$ 100