Net Income Per Common Share (Parenthetical) (Detail) (USD $)	9 Months Ended			9 Months Ended
	Sep. 30, 2012	Oct. 02, 2011 Convertible Notes	Sep. 30, 2012 Convertible Notes	Oct. 02, 2011 Convertible Notes Hedge Warrant	Sep. 30, 2012 Convertible Notes Hedge Warrant	Mar. 31, 2009 Convertible Notes Hedge Warrant
Net Income Loss Per Common Share
Initial debt conversion price	$ 5.48		$ 5.48		$ 7.67	$ 7.67
Shares that would be issued upon conversion	34,703,196	34,700,000		34,700,000