Recent Events - Additional Information (Detail) (USD $)	Jun. 30, 2013	May 17, 2013	Mar. 31, 2013	Dec. 31, 2012
Regulatory Matters [Line Items]
Common stock par value	$ 0.001	$ 0.001		$ 0.001
Common stock, shares authorized	150,000,000	150,000,000	120,000,000	150,000,000