Summary of Warrants and Related Information (Detail) (Warrant, USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013
Warrant
Warrants
Beginning Balance	197,250	253,900	190,000
Granted	0	0
Canceled	0	0
Exercised	0	(56,650)
Expired/Forfeited	(7,250)	0
Ending balance	190,000	197,250	190,000
Exercisable at December 31, 2013			190,000
Weighted-Average Exercise Price
Beginning balance	$ 19.39	$ 17.01	$ 19.80
Granted	$ 0	$ 0
Canceled	$ 0	$ 0
Exercised	$ 0	$ 8.72
Expired/Forfeited	$ 8.72	$ 0
Ending balance	$ 19.80	$ 19.39	$ 19.80
Exercisable at December 31, 2013			$ 19.80