Net Income Per Share - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Earnings Per Share [Abstract]
Common stock equivalents excluded from the calculation of diluted earnings per share due to decline in market price of stock	15,954	361,507	26,566	285,786