Summary of Options Outstanding and Exercisable (Detail) (USD $)	Dec. 31, 2013
$0.88 to $ 4.99
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Minimum	$ 0.88
Exercise Price Maximum	$ 4.99
Weighted Average Remaining Contractual Life (years)	6 years 7 months 10 days
Number of Options Outstanding	960,254
Number of Options Exercisable	467,218
$5.00 to $9.99
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Minimum	$ 5.00
Exercise Price Maximum	$ 9.99
Weighted Average Remaining Contractual Life (years)	10 months 10 days
Number of Options Outstanding	157,325
Number of Options Exercisable	154,304
$10.00 to $39.20
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Minimum	$ 10.00
Exercise Price Maximum	$ 39.20
Weighted Average Remaining Contractual Life (years)	1 month 10 days
Number of Options Outstanding	44,870
Number of Options Exercisable	44,870
$0.88 to $39.20
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Minimum	$ 0.88
Exercise Price Maximum	$ 39.20
Weighted Average Remaining Contractual Life (years)	7 years 6 months 29 days
Number of Options Outstanding	1,162,449
Number of Options Exercisable	666,392