Supplemental Disclosure Of Cash Flow Information and Non-Cash Investing And Financing Activities - Addtional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Jul. 08, 2011	Apr. 30, 2011	Feb. 28, 2009
Supplemental Cash Flow Elements [Line Items]
Interest paid, net	$ 323,000	$ 520,000
Income taxes paid	1,469,000	1,125,000
Line of credit facility, current borrowing capacity					30,000,000
Line of credit facility, maximum borrowing capacity				35,000,000
Business acquisition, purchase price allocation, goodwill amount			9,800,000
Line of credit facility, amount outstanding	13,025,000	16,273,000
Aggregate indebtedness			$ 9,400,000