Stock Incentive Plans - Summary of Non-vested Options (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Options
Options, Non-vested, Granted	45,941
Options, Non-vested, Cancelled
Non-vested options [Member]
Options
Non-vested restricted stock, Beginning balance	821,002	1,313,177	1,339,386
Options, Non-vested, Granted	143,206	89,050	382,050
Options, Non-vested, Vested	(380,413)	(540,050)	(366,484)
Options, Non-vested, Cancelled	(211,288)	(41,175)	(41,775)
Non-vested restricted stock, Ending balance	372,507	821,002	1,313,177
Weighted-average exercise price
Weighted-average exercise price, Beginning balance	$ 15.24	$ 13.58	$ 14.12
Weighted-average exercise price, Granted	$ 8.49	$ 9.72	$ 16.02
Weighted-average exercise price, Vested	$ 12.50	$ 14.77	$ 10.72
Weighted-average exercise price, Cancelled	$ 18.55	$ 15.38	$ 20.39
Weighted-average exercise price, Ending balance	$ 13.57	$ 15.24	$ 13.58