Stock-Based Compensation - Stock Option Activity Under Equity Incentive Plans (Detail) (Stock Options [Member], USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Outstanding, Beginning balance	18,996
Number of Shares, Options granted	3,470
Number of Shares, Options exercised	(1,047)
Number of Shares, Options forfeited and canceled	(764)
Number of Shares, Outstanding, Ending balance	20,655
Number of Shares, Vested and Expected to Vest	20,357
Number of Shares, Exercisable	15,519
Weighted-Average Exercise Price per Share, Outstanding, Beginning balance	$ 9.03
Weighted-Average Exercise Price per Share, Options granted	$ 9.42
Weighted-Average Exercise Price per Share, Options exercised	$ 7.07
Weighted-Average Exercise Price per Share, Options forfeited and Canceled	$ 12.76
Weighted-Average Exercise Price per Share, Outstanding, Ending balance	$ 9.06
Weighted-Average Exercise Price per Share, Vested and expected to vest	$ 9.07
Weighted-Average Exercise Price per Share, Exercisable	$ 9.08
Weighted-Average Remaining Contractual Life, Outstanding	4 years 4 months 6 days
Weighted-Average Remaining Contractual Life, Vested and expected to Vest	4 years 3 months 22 days
Weighted-Average Remaining Contractual Life, Exercisable	3 years 7 months 21 days
Aggregate Intrinsic Value, Outstanding	$ 56,269
Aggregate Intrinsic Value, Vested and expected to Vest	55,454
Aggregate Intrinsic Value, Exercisable	$ 43,287