Stock-Based Compensation Plans - Schedule of Outstanding Options into Two Ranges, Based on Exercise Prices (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	6 Months Ended
	Jun. 30, 2013
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices remaining contractual life, outstanding	3 years 8 months 12 days
Range of exercise prices shares, outstanding	670
Range of exercise prices weighted average exercise price, outstanding	$ 35
Range of exercise prices shares, exercisable	613
Options Exercisable, Weighted Avg. Exercise Price	$ 34
Outstanding Options with Range Based Exercise Prices Set One [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	$ 12.22
Exercise price range, upper range limit	$ 37.45
Range of exercise prices remaining contractual life, outstanding	3 years 2 months 12 days
Range of exercise prices shares, outstanding	337
Range of exercise prices weighted average exercise price, outstanding	$ 25
Range of exercise prices shares, exercisable	328
Options Exercisable, Weighted Avg. Exercise Price	$ 25
Outstanding Options with Range Based Exercise Prices Set Two [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	$ 39.95
Exercise price range, upper range limit	$ 50.30
Range of exercise prices remaining contractual life, outstanding	4 years 1 month 6 days
Range of exercise prices shares, outstanding	333
Range of exercise prices weighted average exercise price, outstanding	$ 45
Range of exercise prices shares, exercisable	285
Options Exercisable, Weighted Avg. Exercise Price	$ 44