Restricted Net Assets - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2013
Minimum
Restricted Net Assets [Line Items]
General reserve percent profit after tax	10.00%
Statutory common reserve percent profit after tax	10.00%
Maximum
Restricted Net Assets [Line Items]
General reserve percent profit after tax	50.00%
Statutory common reserve percent profit after tax	50.00%