Quarterly report pursuant to Section 13 or 15(d)

Income Taxes (Narrative) (Details)

v3.8.0.1
Income Taxes (Narrative) (Details) - USD ($)
$ / shares in Units, $ in Millions
 3 Months Ended 6 Months Ended 9 Months Ended 12 Months Ended
Feb. 28, 2018
Feb. 28, 2017
Nov. 30, 2017
Feb. 28, 2018
Feb. 28, 2017
Dec. 31, 2018
May 31, 2018
Dec. 31, 2017
Income Tax Contingency [Line Items]                
Effective income tax rate 11.70% 34.20%   27.70% 34.10%      
Corporate income tax rate               35.00%
Subsequent Event [Member]                
Income Tax Contingency [Line Items]                
Blended statutory tax rate             29.20%  
Diluted earnings per share related to change in net deferred tax liabilities $ 0.06     $ 0.06        
Diluted earnings per share related to change in annual effective tax rate     $ 0.10          
Scenario, Plan [Member]                
Income Tax Contingency [Line Items]                
Corporate income tax rate           21.00%    
Scenario, Forecast [Member]                
Income Tax Contingency [Line Items]                
Estimated tax benefits $ 56.9     $ 56.9        
Net tax benefit related to change in net deferred tax liabilities $ 20.8     $ 20.8        
Net tax benefit related to change in annual effective tax rate     $ 36.1