Schedule of Significant Option Groups Outstanding (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Shares	2,706
Options Exercisable, Shares	1,814
Options Outstanding, Weighted-Average Exercise Price	$ 6.29
Options Exercisable, Weighted-Average Exercise Price	$ 4.55
$0.94 - $2.58
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	5 years 11 months 19 days
Options Outstanding, Shares	485
Options Exercisable, Shares	436
Range Of Exercise Prices, Lower Limit	$ 0.94
Range Of Exercise Prices, Upper Limit	$ 2.58
Options Outstanding, Weighted-Average Exercise Price	$ 1.83
Options Exercisable, Weighted-Average Exercise Price	$ 1.79
$2.67 - $2.74
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	5 years 4 months 21 days
Options Outstanding, Shares	821
Options Exercisable, Shares	545
Range Of Exercise Prices, Lower Limit	$ 2.67
Range Of Exercise Prices, Upper Limit	$ 2.74
Options Outstanding, Weighted-Average Exercise Price	$ 2.69
Options Exercisable, Weighted-Average Exercise Price	$ 2.70
$3.23 - $7.71
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	3 years 9 months 18 days
Options Outstanding, Shares	674
Options Exercisable, Shares	590
Range Of Exercise Prices, Lower Limit	$ 3.23
Range Of Exercise Prices, Upper Limit	$ 7.71
Options Outstanding, Weighted-Average Exercise Price	$ 5.15
Options Exercisable, Weighted-Average Exercise Price	$ 5.00
$9.34 - $16.95
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	4 years 7 months 21 days
Options Outstanding, Shares	726
Options Exercisable, Shares	243
Range Of Exercise Prices, Lower Limit	$ 9.34
Range Of Exercise Prices, Upper Limit	$ 16.95
Options Outstanding, Weighted-Average Exercise Price	$ 14.39
Options Exercisable, Weighted-Average Exercise Price	$ 12.58