Net Income (Loss) Per Share - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Earnings Per Share [Abstract]
Unvested restricted common stock included	27,000		27,000
Unvested restricted common stock yet not included		100,000		100,000
Options to purchase yet not included	1,300,000	5,300,000	1,300,000	5,300,000