Reconciliation of Income Tax Expense (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012
Reconciliation Of Income Taxes [Line Items]
Provision at federal statutory tax rate									$ 2,496	$ 1,868
State income tax-net of federal tax benefit									214	102
Tax-exempt interest income									(402)	(353)
Increase in cash value of life insurance									(54)	(62)
Other									1	4
Totals	$ 534	$ 653	$ 557	$ 511	$ 551	$ 218	$ 427	$ 363	$ 2,255	$ 1,559
Effective tax rate									30.70%	28.40%