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, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Securities to be Issued Upon Exercise of Outstanding Options & Vesting of RSUs	19,116
Number of Securities Remaining Available for Issuance Under Equity Compensation Plans (Excluding Securities Reflected in Column)	10,800
Weighted-Average Exercise Price of Outstanding Options	$ 9.03
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 & Vesting of RSUs	12,292
Number of Securities Remaining Available for Issuance Under Equity Compensation Plans (Excluding Securities Reflected in Column)	10,800
Weighted-Average Exercise Price of Outstanding Options	$ 8.66
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 & Vesting of RSUs	6,824
Weighted-Average Exercise Price of Outstanding Options	$ 9.71