Condensed Balance Sheets (Parenthetical) (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Oct. 31, 2008
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, issued	0	0
Preferred stock, outstanding	0	0
Par value of common stock issued	$ 0.0001	$ 0.0001	$ 0.0001
Common stock, shares authorized	75,000,000	75,000,000
Common stock, shares issued	30,295,955	30,084,883
Common stock, shares outstanding	30,031,908	29,820,836
Treasury stock, shares	264,047	264,047
Parent
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, issued	0	0
Preferred stock, outstanding	0	0
Par value of common stock issued	$ 0.0001	$ 0.0001
Common stock, shares authorized	75,000,000	75,000,000
Common stock, shares issued	30,295,955	30,084,883
Common stock, shares outstanding	30,031,908	29,820,836
Treasury stock, shares	264,047	264,047