Stockholders' Equity - Summary of Company's Restricted Stock Award Activity (Detail)	3 Months Ended		6 Months Ended	12 Months Ended
	Sep. 30, 2013	Mar. 31, 2013	Sep. 30, 2013	Dec. 31, 2012
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Beginning balance, Unvested, Number of Shares		1,162,044	985,742	1,111,295
Granted, Number of Shares		55,000	60,000	1,380,000
Vested, Number of Shares	(296,250)	(196,612)	(356,250)	(1,143,735)
Canceled / forfeited, Number of Shares		(34,690)		(185,516)
Ending balance, Unvested, Number of Shares	689,492	985,742	689,492	1,162,044