Subsequent Events - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2013
2007 Stock Incentive Plan [Member]
Subsequent Event [Line Items]
Further stock option Granted	3,636
Subsequent Event [Member] | 2013 Stock Incentive Plan [Member]
Subsequent Event [Line Items]
Number of shares of Common Stock reserved for issuance	909,090
Number of shares equal to the sum of the number of shares of Common Stock	3,844,993
Annual increase shares of Common Stock	2,000,000
Percentage of Common Stock shares outstanding shares	4.00%
Subsequent Event [Member] | 2007 Stock Incentive Plan [Member]
Subsequent Event [Line Items]
Further stock option Granted	0