Schedule Of Additional Information Of Stock-Based Compensation (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding options, Weighted-average remaining contractual term (in years)	3 years 8 months 19 days		2 years 11 months 12 days
Outstanding options, Aggregate intrinsic value	$ 99,212		$ 94,270
Exercisable options, Weighted-average remaining contractual term (in years)	2 years 3 months 15 days		1 year 10 months 21 days
Exercisable options, Aggregate intrinsic value	69,472		59,097
Unrecognized compensation	$ 32,808	[1]	$ 30,299	[1]
Unrecognized compensation, Weighted average period of expected recognition (in years)	8 months 27 days	[1]	1 year 8 months 5 days	[1]

[1] Includes restricted stock