Stockholders' Equity - Additional Information (Detail)	Sep. 30, 2013	Apr. 25, 2013	Mar. 31, 2013	Dec. 31, 2012
Equity [Abstract]
Common stock, shares authorized	95,000,000	95,000,000	45,000,000	45,000,000
Common stock, shares outstanding	43,139,027			32,204,720