Stock-Based Compensation - Stock-Based Compensation Price Range Information (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]
Number of outstanding options	8,986
Weighted average remaining life, Outstanding options	6 years 8 months 12 days
Weighted average exercise price, Outstanding options	$ 4.99
Number of exercisable	4,777
Weighted average exercise price, Exercisable options	$ 6.20
$0 to $18 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower limit	$ 0
Upper limit	$ 18
$0 to $3 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of outstanding options	2,526
Weighted average remaining life, Outstanding options	8 years 1 month 6 days
Weighted average exercise price, Outstanding options	$ 1.50
Number of exercisable	806
Weighted average exercise price, Exercisable options	$ 1.61
Lower limit	$ 0
Upper limit	$ 3
$3 to $6 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of outstanding options	3,784
Weighted average remaining life, Outstanding options	7 years 7 months 6 days
Weighted average exercise price, Outstanding options	$ 4.54
Number of exercisable	1,534
Weighted average exercise price, Exercisable options	$ 3.95
Lower limit	$ 3
Upper limit	$ 6
$6 to $9 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of outstanding options	1,761
Weighted average remaining life, Outstanding options	4 years 10 months 24 days
Weighted average exercise price, Outstanding options	$ 7.33
Number of exercisable	1,522
Weighted average exercise price, Exercisable options	$ 7.42
Lower limit	$ 6
Upper limit	$ 9
$9 to $12 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of outstanding options	555
Weighted average remaining life, Outstanding options	3 years
Weighted average exercise price, Outstanding options	$ 11.62
Number of exercisable	555
Weighted average exercise price, Exercisable options	$ 11.62
Lower limit	$ 9
Upper limit	$ 12
$12 to $15 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of outstanding options	356
Weighted average remaining life, Outstanding options	2 years 4 months 24 days
Weighted average exercise price, Outstanding options	$ 12.53
Number of exercisable	356
Weighted average exercise price, Exercisable options	$ 12.53
Lower limit	$ 12
Upper limit	$ 15
$15 to $18 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of outstanding options	4
Weighted average remaining life, Outstanding options	2 years
Weighted average exercise price, Outstanding options	$ 15.45
Number of exercisable	4
Weighted average exercise price, Exercisable options	$ 15.45
Lower limit	$ 15
Upper limit	$ 18