Annual and transition report of foreign private issuers pursuant to Section 13 or 15(d)

Equity (Schedule of Stock Option Activity) (Details)

v3.8.0.1
Equity (Schedule of Stock Option Activity) (Details)
 12 Months Ended
Dec. 31, 2017
$ / shares
shares
Number of Options  
Options Outstanding as of December 31, 2016 | shares 2,615,461
Granted | shares 2,139,698
Exercised | shares (604,536)
Forfeited | shares (819,670)
Options Outstanding as of December 31, 2017 | shares 3,330,953
Options exercisable as of December 31, 2017 | shares 1,109,094
Weighted Average Exercise Price  
Options Outstanding as of December 31, 2016 | $ / shares $ 37.21
Granted | $ / shares 20.41
Exercised | $ / shares 10.84
Forfeited | $ / shares 35.89
Options Outstanding as of December 31, 2017 | $ / shares 31.53
Options exercisable as of December 31, 2017 | $ / shares $ 49.68