Warrants Issued and Outstanding (Detail) (Warrants, USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Warrants
Warrants Outstanding Number of underlying shares
Beginning Balance	283,956	408,956	1,138,420
Granted / Vested	0	0	0
Forfeited	0	0	0
Exercised	(255,500)	(125,000)	(729,464)
Ending Balance	28,456	283,956	408,956
Warrants Outstanding Weighted Average Exercise Price
Beginning Balance	$ 3.63	$ 3.59	$ 3.62
Exercised	$ 3.50	$ 3.50	$ 3.63
Ending Balance	$ 4.80	$ 3.63	$ 3.59
Warrants Outstanding Average Remaining Contractual Life (yrs)
Beginning Balances			2 years 10 months 28 days
Ending Balance	8 months 5 days	10 months 28 days	1 year 10 months 20 days
Warrants Exercisable Number of underlying shares
Beginning Balance	283,956	408,956	1,138,420
Ending Balance	28,456	283,956	408,956
Warrants Exercisable Weighted Average Exercise Price
Beginning Balance	$ 3.63	$ 3.59	$ 3.62
Ending Balance	$ 4.80	$ 3.63	$ 3.59
Warrants Exercisable Average Remaining Contractual Life (yrs)
Beginning Balance			2 years 10 months 28 days
Ending Balance	8 months 5 days	10 months 28 days	1 year 10 months 20 days