Stock-Based Compensation -Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified		12 Months Ended
	Dec. 31, 2013	Dec. 31, 2013 Restricted stock units	Dec. 31, 2012 Restricted stock units	Dec. 31, 2011 Restricted stock units	Dec. 31, 2013 Selling, General and Administrative Expense	Dec. 31, 2012 Selling, General and Administrative Expense	Dec. 31, 2011 Selling, General and Administrative Expense	Dec. 31, 2004 Subsequent Event [Member]	Dec. 31, 2004 Maximum [Member]	Dec. 31, 2013 Maximum [Member] Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum aggregate number of shares of common stock that may be issued in connection with stock options, stock appreciation rights, restricted stock, restricted stock units and performance award									6,600,000
Reduction in number of shares available for grant, for every one restricted share or restricted stock unit awarded								2
Shares available to be awarded under the plan	1,852,136
Stock-based compensation expense					$ 10.0	$ 7.2	$ 7.7
Maximum vesting period for restricted stock units outstanding										6 years
Weighted average grant date fair value of restricted stock units granted		$ 42.47	$ 42.50	$ 36.98
Fair value of restricted stock units released		6.5	5.7	13.7
Unrecognized compensation expense related to restricted stock units		$ 19.3
Cost expected to be recognized over a period		3 years 8 months 0 days