Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity (Stock Option Plan and Restricted Stock Activity) (Details)

v3.5.0.2
Stockholders' Equity (Stock Option Plan and Restricted Stock Activity) (Details)
6 Months Ended
Jun. 30, 2016
$ / shares
shares
Stock Options:  
Balance as of December 31, 2015 | shares 1,683,341
Granted | shares 254,989
Exercised | shares (77,243)
Forfeited | shares (24,282)
Balance as of June 30, 2016 | shares 1,836,805
Weighted Average Exercise Price (in USD per share)  
Balance as of December 31, 2015 | $ / shares $ 34.23
Granted | $ / shares 90.51
Exercised | $ / shares 30.73
Forfeited | $ / shares 61.99
Balance as of June 30, 2016 | $ / shares $ 41.83
Restricted Stock [Member]  
Restricted Shares:  
Nonvested at December 31, 2015 | shares 130,749
Granted | shares 233,955
Exercised | shares (41,833)
Forfeited | shares (1,850)
Nonvested at June 30, 2016 | shares 321,021
Weighted- Average Grant Date Fair Value (in USD per share)  
Nonvested at December 31, 2015 | $ / shares $ 60.36
Granted | $ / shares 94.76
Exercised | $ / shares 52.18
Forfeited | $ / shares 71.48
Nonvested at March 31, 2016 | $ / shares $ 73.13