Stock Incentive Plans - Summary of the Non-vested Options (Detail) (Non-vested options [Member], USD $)	9 Months Ended
	Sep. 30, 2013
Non-vested options [Member]
Options
Non-vested restricted stock, Beginning balance	821,002
Options, Non-vested, Granted	82,815
Options, Non-vested, Vested	(249,787)
Options, Non-vested, Forfeited	(205,500)
Non-vested restricted stock, Ending balance	448,530
Weighted-average exercise price
Weighted-average exercise price, Beginning balance	$ 15.24
Weighted-average exercise price, Granted	$ 7.79
Weighted-average exercise price, Vested	$ 10.69
Weighted-average exercise price, Forfeited	$ 18.70
Weighted-average exercise price, Ending balance	$ 14.82