Schedule of Exercise Price Ranges, Characteristics of Outstanding Stock Options (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013
$17.83-$29.33
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, minimum	$ 17.83
Range of Exercise Prices, maximum	$ 29.33
Stock Options Outstanding, Shares	609,820
Stock Options Outstanding, Weighted-Average Exercise Price	$ 21.76
Stock Options Outstanding, Weighted-Average Remaining Life, in years	5 years 6 months
Stock Options Exercisable, Shares	609,820
Exercisable, Weighted-Average Exercise Price	$ 21.76
Stock Options Exercisable, Weighted-Average Remaining Life, in years	5 years 6 months
$33.55-$40.88
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, minimum	$ 33.55
Range of Exercise Prices, maximum	$ 40.88
Stock Options Outstanding, Shares	560,795
Stock Options Outstanding, Weighted-Average Exercise Price	$ 37.34
Stock Options Outstanding, Weighted-Average Remaining Life, in years	5 years 6 months 30 days
Stock Options Exercisable, Shares	246,903
Exercisable, Weighted-Average Exercise Price	$ 39.80
Stock Options Exercisable, Weighted-Average Remaining Life, in years	2 years 10 months 24 days
$41.26-$49.92
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, minimum	$ 41.26
Range of Exercise Prices, maximum	$ 49.92
Stock Options Outstanding, Shares	524,765
Stock Options Outstanding, Weighted-Average Exercise Price	$ 46.42
Stock Options Outstanding, Weighted-Average Remaining Life, in years	5 years 4 months 30 days
Stock Options Exercisable, Shares	321,934
Exercisable, Weighted-Average Exercise Price	$ 45.10
Stock Options Exercisable, Weighted-Average Remaining Life, in years	3 years 1 month 6 days
$17.83-$49.92
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, minimum	$ 17.83
Range of Exercise Prices, maximum	$ 49.92
Stock Options Outstanding, Shares	1,695,380
Stock Options Outstanding, Weighted-Average Exercise Price	$ 34.55
Stock Options Outstanding, Weighted-Average Remaining Life, in years	5 years 5 months 30 days
Stock Options Exercisable, Shares	1,178,657
Exercisable, Weighted-Average Exercise Price	$ 31.91
Stock Options Exercisable, Weighted-Average Remaining Life, in years	4 years 3 months 18 days