Stock Incentive Plans - Summary of Non-vested Options (Detail) (USD $)	1 Months Ended				2 Months Ended		3 Months Ended	7 Months Ended		12 Months Ended
	Sep. 30, 2014	Oct. 31, 2013	Jul. 31, 2012	Jan. 31, 2012	Oct. 31, 2012	May 31, 2012	Dec. 31, 2014	Jul. 31, 2014	Jul. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Options
Options, Granted	300,000	14,450	7,000	8,500	36,800	36,750	235,650	39,300	82,815	574,950	97,265	89,050
Weighted-average exercise price
Weighted-average exercise price, Granted										$ 5.04	$ 8.43	$ 9.72
Weighted-average exercise price, Cancelled										$ 16.72	$ 18.31	$ 15.13
Non-vested Options [Member]
Options
Options, Non-vested, Beginning balance				1,313,177				326,566	821,002	326,566	821,002	1,313,177
Options, Granted										574,950	97,265	89,050
Options, Vested										(169,361)	(380,413)	(540,050)
Options, Cancelled										(103,422)	(211,288)	(41,175)
Options, Non-vested, Ending balance							628,733			628,733	326,566	821,002
Weighted-average exercise price
Weighted-average exercise price, Beginning balance				13.58				13.57	15.24	$ 13.57	$ 15.24	$ 13.58
Weighted-average exercise price, Granted										$ 5.04	$ 8.43	$ 9.72
Weighted-average exercise price, Vested										$ 14.84	$ 12.50	$ 14.77
Weighted-average exercise price, Cancelled										$ 12.74	$ 18.55	$ 15.38
Weighted-average exercise price, Ending balance							5.93			$ 5.93	$ 13.57	$ 15.24