Stockholders' Equity - Summary of Options Activity (Detail) (USD $)	3 Months Ended
	Mar. 31, 2013
Number of Shares
Options outstanding, beginning balance	693,672
Granted	0
Forfeited	(23,100)
Expired	(15,183)
Options outstanding, ending balance	655,389
Vested and expected to vest at end of period	615,320
Options exercisable at end of period	183,987
Weighted Average Exercise Price
Forfeited	$ 7.93
Expired	$ 11.86
Options outstanding, ending balance	$ 6.05
Vested and expected to vest at end of period	$ 6.31
Options exercisable at end of period	$ 16.47
Weighted Average Remaining Life (In Years)
Options outstanding at end of the year	7 years 10 months 24 days
Vested and expected to vest at end of period	7 years 10 months 24 days
Options exercisable at end of period	5 years 2 months 12 days