Summary of Changes in RSUs (Detail) (Restricted Stock Units, USD $)	6 Months Ended
	Jun. 30, 2011
Restricted Stock Units
Restricted Stock Units
Beginning Balance	3,868,271
Granted	668,458	[1]
Vested	(1,390,310)
Forfeited	(84,126)
Ending Balance	3,062,293	[2],[3]
Per Share Weighted Average Grant Date Fair Value
Beginning Balance	$ 16.52
Granted	$ 38.07	[1]
Vested	$ 17.17
Forfeited	$ 20.20
Ending Balance	$ 21.48	[2],[3]

[1] The 0.7 million RSUs granted in 2011 consisted of 0.3 million performance-based RSUs awarded to executives and 0.4 million service-based RSUs awarded to non-executive employees and certain board members. The 0.3 million performance-based RSUs represents the target amount of the award. The actual number of performance-based RSUs that will ultimately be granted will be between 0% and 200% of the target amount, depending on the performance metric achieved. For 2011, the performance metric is the dollar level of the Company's subscription-based contract value at December 31, 2011. If the specified minimum level of achievement is not met, the performance-based RSUs will be forfeited in their entirety, and any compensation expense already recorded will be reversed.

[2] The Company expects that substantially all of the outstanding awards will vest in future periods.

[3] The weighted-average remaining contractual term of the outstanding RSUs is approximately 1.5 years.