Stockholders' Equity - Summarization of Common Stock Shares for Issuance Under Existing Equity Compensation Plans (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Securities to be Issued Upon Exercise of Outstanding Options	21,995
Number of Securities Remaining Available for Issuance Under Equity Compensation Plans (Excluding Securities Reflected in Column)	2,812
Weighted-Average Exercise Price of Outstanding Options	$ 10.50
Equity Compensation Plans Approved by Security Holders [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Securities to be Issued Upon Exercise of Outstanding Options	18,601
Number of Securities Remaining Available for Issuance Under Equity Compensation Plans (Excluding Securities Reflected in Column)	2,812
Weighted-Average Exercise Price of Outstanding Options	$ 10.68
Equity Compensation Plans Not Approved by Security Holders [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Securities to be Issued Upon Exercise of Outstanding Options	3,394
Weighted-Average Exercise Price of Outstanding Options	$ 9.52