Stockholders' Equity - Schedule of Stock Options Outstanding and Exercisable (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Options Outstanding, Number	2,334
Weighted-Average Remaining Contractual Term (In Years)	8 years 2 months 12 days	8 years
Options Outstanding, Weighted-Average Exercise Price	$ 17.33
Options Exercisable, Number	930
Options Exercisable, Weighted-Average Exercise Price	$ 11.72
$0.08 - $0.14
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price Range Lower Limit	$ 0.08
Exercise Price Range Upper Limit	$ 0.14
Options Outstanding, Number	29
Weighted-Average Remaining Contractual Term (In Years)	1 year 1 month 6 days
Options Outstanding, Weighted-Average Exercise Price	$ 0.09
Options Exercisable, Number	29
Options Exercisable, Weighted-Average Exercise Price	$ 0.09
$0.14 - $1.90
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price Range Lower Limit	$ 0.14
Exercise Price Range Upper Limit	$ 1.90
Options Outstanding, Number	3
Weighted-Average Remaining Contractual Term (In Years)	4 years 6 months
Options Outstanding, Weighted-Average Exercise Price	$ 1.34
Options Exercisable, Number	3
Options Exercisable, Weighted-Average Exercise Price	$ 1.34
$2.04 - $8.18
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price Range Lower Limit	$ 2.04
Exercise Price Range Upper Limit	$ 8.18
Options Outstanding, Number	224
Weighted-Average Remaining Contractual Term (In Years)	5 years 8 months 12 days
Options Outstanding, Weighted-Average Exercise Price	$ 3.66
Options Exercisable, Number	224
Options Exercisable, Weighted-Average Exercise Price	$ 3.65
$11.45 - $17.41
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price Range Lower Limit	$ 11.45
Exercise Price Range Upper Limit	$ 17.41
Options Outstanding, Number	1,194
Weighted-Average Remaining Contractual Term (In Years)	7 years 9 months 18 days
Options Outstanding, Weighted-Average Exercise Price	$ 14.87
Options Exercisable, Number	642
Options Exercisable, Weighted-Average Exercise Price	$ 14.53
$17.50 - $27.64
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price Range Lower Limit	$ 17.50
Exercise Price Range Upper Limit	$ 27.64
Options Outstanding, Number	709
Weighted-Average Remaining Contractual Term (In Years)	9 years 6 months
Options Outstanding, Weighted-Average Exercise Price	$ 23.76
Options Exercisable, Number	28
Options Exercisable, Weighted-Average Exercise Price	$ 22.66
$27.91 - $29.14
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price Range Lower Limit	$ 27.91
Exercise Price Range Upper Limit	$ 29.14
Options Outstanding, Number	175
Weighted-Average Remaining Contractual Term (In Years)	9 years 10 months 24 days
Options Outstanding, Weighted-Average Exercise Price	$ 28.71
Options Exercisable, Number	4
Options Exercisable, Weighted-Average Exercise Price	$ 28.68