Annual report pursuant to Section 13 and 15(d)

Annual report pursuant to Section 13 and 15(d)

Stock Compensation - Status of Our Stock Options (Detail)

v3.10.0.1
Stock Compensation - Status of Our Stock Options (Detail) - $ / shares
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]      
Number of shares, outstanding 6,342,526 5,136,110 5,326,505
Granted 2,457,102 2,119,498 2,617,526
Number of shares, exercised (1,570,211) (565,569) (2,483,519)
Number of shares, forfeited (390,000) (347,513) (324,402)
Number of shares, outstanding 6,839,417 6,342,526 5,136,110
Number of shares, exercisable 2,508,890    
Weighted average exercise price, outstanding (in dollars per share) $ 6.51 $ 5.76 $ 3.07
Weighted average exercise price, granted (in dollars per share) 9.03 7.60 7.14
Weighted average exercise price, exercised (in dollars per share) 5.48 3.84 1.69
Weighted average exercise price, forfeited (in dollars per share) 7.15 6.12 3.99
Weighted average exercise price, outstanding (in dollars per share) 7.63 $ 6.51 $ 5.76
Weighted average exercise price, exercisable (in dollars per share) $ 6.42