XML 63 R53.htm IDEA: XBRL DOCUMENT v3.8.0.1
Stock-Based Compensation - Restricted Stock (Details) - Restricted stock
$ / shares in Units, shares in Thousands, $ in Millions
 3 Months Ended
Dec. 31, 2017
USD ($)
$ / shares
shares
Common-stock based award plan  
Unrecognized compensation cost (in dollars) | $ $ 54.2
Weighted-average period over which unrecognized compensation cost is expected to be recognized 3 years
Restricted stock awards activity, shares  
Unvested at the beginning of the period (in shares) | shares 659
Granted (in shares) | shares 617
Vested (in shares) | shares (248)
Forfeited (in shares) | shares (1)
Unvested at the end of the period (in shares) | shares 1,027
Restricted stock awards activity, weighted average grant date fair value  
Unvested at the beginning of the period (in dollars per share) | $ / shares $ 70.76
Granted (in dollars per share) | $ / shares 59.39
Vested (in dollars per share) | $ / shares 71.06
Forfeited (in dollars per share) | $ / shares 69.48
Unvested at the end of the period (in dollars per share) | $ / shares $ 63.72
Minimum  
Common-stock based award plan  
Vesting period 3 years
Maximum  
Common-stock based award plan  
Vesting period 6 years