Net Income Per Share - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Earnings Per Share [Abstract]
Options to purchase shares of common stock	1,600,000	1,100,000	1,500,000	865,000.0
Exercise prices greater than the average fair market value of stock	$ 10.85	$ 12.79	$ 11.03	$ 10.39