Employee Benefit Plans - Summary of Company's Stock Option and Restricted Stock Unit Activity (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items]
Shares Available for Grant, Beginning balance	7,835,000
Shares Available for Grant, Authorized	5,463,000
Shares Available for Grant, Granted	(5,145,000)
Shares Available for Grant, Options exercised
Shares Available for Grant, Shares released
Shares Available for Grant, Forfeited or cancelled	2,002,000
Shares Available for Grant, Ending balance	10,155,000
Restricted Stock Units Outstanding [Member]
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items]
Number of Units, Beginning balance	3,713,000
Number of Shares, Authorized
Number of Units, Granted	2,569,000
Number of Units, Shares released	(1,663,000)
Number of Units, Forfeited or cancelled	(681,000)
Number of Units, Ending balance	3,938,000
Weighted Average Grant Date Fair Value, Beginning balance	7.52
Weighted Average Grant Date Fair Value, Authorized
Weighted Average Grant Date Fair Value, Granted	5.70
Weighted Average Grant Date Fair Value, Shares released	7.37
Weighted Average Grant Date Fair Value, Forfeited or cancelled	6.50
Weighted Average Grant Date Fair Value, Ending balance	6.44
Stock Options Outstanding [Member]
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items]
Number of Shares, Beginning balance	9,303,000
Number of Shares, Authorized
Number of Shares, Granted	1,292,000
Number of Shares, Options exercised	(317,000)
Number of Shares, Forfeited or cancelled	(1,378,000)
Number of Shares, Ending balance	8,900,000
Weighted Average Exercise Price, Beginning balance	7.12
Weighted Average Exercise Price, Authorized
Weighted Average Exercise Price, Granted	5.60
Weighted Average Exercise Price, Options exercised	2.80
Weighted Average Exercise Price, Forfeited or cancelled	8.57
Weighted Average Exercise Price, Ending balance	6.83