Subsequent Events (Detail) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended	1 Months Ended	2 Months Ended	1 Months Ended	2 Months Ended
	Dec. 31, 2013	Jan. 31, 2014 Subsequent event Employee stock purchase plan	Feb. 26, 2014 Subsequent event Stock options	Jan. 31, 2014 Subsequent event Stock options 2010 Plan	Feb. 26, 2014 Subsequent event Restricted Stock Units (RSUs) [Member]
Subsequent Event [Line Items]
Contractual Obligation, Due in Second Year	$ 15.2
Increase in shares authorized under plan		524,699		2,361,145
Stock options granted (in shares)	2,394,000		284,670		10,500
Stock options granted, weighted average exercise price (in usd per share)	$ 43.32		$ 55.51
Award vesting period			4 years		4 years
Contractual Obligation, Due in Next Twelve Months	15.3
Contractual Obligation, Due in Third Year	$ 3.8