Computation of Basic and Diluted Net Income Per Common Share (Parenthetical) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Mar. 31, 2009
Net Income Loss Per Common Share
Initial debt conversion price	$ 5.48
Shares that would be issued upon conversion	34,703,196
Convertible Notes
Net Income Loss Per Common Share
Initial debt conversion price	$ 5.48
Shares that would be issued upon conversion	34,700,000
Convertible Notes Hedge Warrant
Net Income Loss Per Common Share
Initial debt conversion price	$ 7.67	$ 7.67
Shares that would be issued upon conversion	34,700,000