Summary Information about Options Outstanding (Detail) (USD $)	6 Months Ended
	Jun. 30, 2014
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Prices, lower limit	$ 5.20
Range of Exercise Prices, upper limit	$ 43.40
Options Number Outstanding	773,602
Options Outstanding Weighted Average Remaining Contractual Life (Years)	7 years 5 months 1 day
Options Outstanding Weighted Average Exercise Price	$ 12.47
Options Number Exercisable	320,135
Options Exercisable Weighted Average Exercise Price	$ 18.27
Range 1
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Prices, lower limit	$ 5.20
Range of Exercise Prices, upper limit	$ 8.00
Options Number Outstanding	188,763
Options Outstanding Weighted Average Remaining Contractual Life (Years)	9 years 15 days
Options Outstanding Weighted Average Exercise Price	$ 6.50
Options Number Exercisable	34,124
Options Exercisable Weighted Average Exercise Price	$ 7.46
Range 2
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Prices, lower limit	$ 8.10
Range of Exercise Prices, upper limit	$ 8.40
Options Number Outstanding	16,496
Options Outstanding Weighted Average Remaining Contractual Life (Years)	8 years 4 months 10 days
Options Outstanding Weighted Average Exercise Price	$ 8.38
Options Number Exercisable	16,413
Options Exercisable Weighted Average Exercise Price	$ 8.38
Range 3
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Prices, lower limit	$ 8.50
Range of Exercise Prices, upper limit	$ 8.80
Options Number Outstanding	266,500
Options Outstanding Weighted Average Remaining Contractual Life (Years)	9 years 8 months 12 days
Options Outstanding Weighted Average Exercise Price	$ 8.80
Options Number Exercisable	333
Options Exercisable Weighted Average Exercise Price	$ 8.80
Range 4
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Prices, lower limit	$ 8.90
Range of Exercise Prices, upper limit	$ 14.40
Options Number Outstanding	158,065
Options Outstanding Weighted Average Remaining Contractual Life (Years)	5 years 9 months 4 days
Options Outstanding Weighted Average Exercise Price	$ 12.20
Options Number Exercisable	129,426
Options Exercisable Weighted Average Exercise Price	$ 11.88
Range 5
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Prices, lower limit	$ 14.50
Range of Exercise Prices, upper limit	$ 43.40
Options Number Outstanding	143,778
Options Outstanding Weighted Average Remaining Contractual Life (Years)	2 years 9 months 22 days
Options Outstanding Weighted Average Exercise Price	$ 27.88
Options Number Exercisable	139,839
Options Exercisable Weighted Average Exercise Price	$ 28.01