Share-Based Compensation Plans (Summary of Stock Option Activity) (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Beginning Balance, Number outstanding	1,270
Exercised during 2014, Number outstanding	(326)
Ending Balance, Number outstanding	944
Vested and expected to vest at March 31, 2014, Number outstanding	944
Exercisable at March 31, 2014, Number outstanding	811
Beginning Balance, Weighted-average exercise price	$ 18.03
Exercised during 2014, Weighted-average exercise price	$ 13.82
Ending Balance, Weighted-average exercise price	$ 19.49
Vested and expected to vest at March 31, 2014, Weighted-average exercise price	$ 19.49
Exercisable at March 31, 2014, Weighted-average exercise price	$ 18.16
Ending Balance, Weighted-average remaining contractual term, years	2 years 6 months
Vested and expected to vest at March 31, 2014, Weighted-average remaining contractual term, years	2 years 6 months
Exercisable at March 31, 2014, Weighted-average remaining contractual term, years	1 year 3 months 18 days
Ending Balance, Aggregate intrinsic value	$ 6,809
Vested and expected to vest at March 31, 2014, Aggregate intrinsic value	6,809
Exercisable at March 31, 2014, Aggregate intrinsic value	$ 6,809