Stockholders' Equity - Summary of Common Shares Reserved for Future Issuance (Detail)	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shares of common stock reserved for issuance	14,660,000	10,209,000
Stock options outstanding under the 2009 Omnibus Incentive Compensation Plan and previous plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shares of common stock reserved for issuance	3,065,000	3,933,000
Restricted stock units outstanding
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shares of common stock reserved for issuance	1,629,000	1,108,000
Future grants of awards under the 2009 Omnibus Incentive Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shares of common stock reserved for issuance	4,463,000	3,668,000
Shares available under the Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shares of common stock reserved for issuance	1,385,000	1,500,000
Common stock warrants outstanding
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shares of common stock reserved for issuance	4,118,000	0