Stock-Based Compensation (Company's Activities With Respect To Its Stock Options) (Detail) (USD $) Share data in Thousands, except Per Share data, unless otherwise specified	6 Months Ended
	Jun. 30, 2012
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Shares, Outstanding at December 31, 2011	3,608
Number of Shares, Granted	613
Number of Shares, Exercised	(504)
Number of Shares, Canceled	(7)
Number of Shares, Outstanding at June 30, 2012	3,710
Number of Shares, Exercisable at June 30, 2012	2,150
Number of Shares, Unvested at June 30, 2012	1,560
Weighted-Average Exercise Price Per Share, Outstanding at December 31, 2011	$ 28.06
Weighted-Average Exercise Price Per Share, Granted	$ 47.58
Weighted-Average Exercise Price Per Share, Exercised	$ 27.68
Weighted-Average Exercise Price Per Share, Canceled	$ 41.93
Weighted-Average Exercise Price Per Share, Outstanding at June 30, 2012	$ 31.31
Weighted-Average Exercise Price Per Share, Exercisable at June 30, 2012	$ 25.44
Weighted-Average Exercise Price Per Share, Unvested at June 30, 2012	$ 39.39
Weighted-Average Remaining Contractual Life (in years), Outstanding at June 30, 2012	4 years 2 months 9 days
Weighted-Average Remaining Contractual Life (in years), Exercisable at June 30, 2012	3 years 1 month 24 days
Weighted-Average Remaining Contractual Life (in years), Unvested at June 30, 2012	5 years 7 months 17 days