Loans - Composition of Nonaccrual Loans and Impaired Loans (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Debt Disclosure [Abstract]
Loans on nonaccrual	$ 2,549,000	$ 4,471,000	$ 5,827,000
Loans 90 days past due and still accruing			18,000
Impaired loans on nonaccrual included above	1,819,000	2,878,000	3,468,000
Total recorded investment in impaired loans	7,788,000	5,925,000	8,102,000
Average recorded investment of impaired loans	6,776,000	7,043,000	10,284,000
Accruing troubled debt restructures	5,969,000	3,048,000	4,634,000
Interest income not recorded on nonaccrual loans according to their original terms	711,000	753,000	846,000
Interest income on nonaccrual loans actually recorded
Interest income recognized on impaired loans	$ 161,000	$ 180,000	$ 155,000