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)
3 Months Ended
Mar. 31, 2016
$ / shares
shares
Stock Options:  
Balance as of December 31, 2015 | shares 1,683,341
Granted | shares 241,015
Exercised | shares (44,029)
Balance as of March 31, 2016 | shares 1,880,327
Weighted Average Exercise Price (in USD per share)  
Balance as of December 31, 2015 | $ / shares $ 34.23
Granted | $ / shares 88.84
Exercised | $ / shares 23.00
Balance as of March 31, 2016 | $ / shares $ 41.50
Restricted Stock [Member]  
Restricted Shares:  
Nonvested at December 31, 2015 | shares 130,749
Granted | shares 229,847
Exercised | shares (34,649)
Nonvested at March 31, 2016 | shares 325,947
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
Nonvested at March 31, 2016 | $ / shares $ 72.88