Annual report pursuant to Section 13 and 15(d)

Income Taxes (Components of Provision for Income Taxes) (Details)

v3.5.0.2
Income Taxes (Components of Provision for Income Taxes) (Details) - USD ($)
$ in Millions
3 Months Ended 12 Months Ended
May 31, 2016
Feb. 29, 2016
Nov. 30, 2015
Aug. 31, 2015
May 31, 2015
Feb. 28, 2015
Nov. 30, 2014
Aug. 31, 2014
May 31, 2016
May 31, 2015
May 31, 2014
Income Taxes [Abstract]                      
Federal                 $ 336.4 $ 341.4 $ 314.5
State                 50.8 47.8 51.0
Total current                 387.2 389.2 365.5
Federal                 5.5 (5.1) (3.5)
State                 1.6 1.0 (1.4)
Total deferred                 7.1 (4.1) (4.9)
Income taxes $ 98.0 $ 101.3 $ 106.6 $ 88.4 $ 92.4 $ 96.5 $ 98.6 $ 97.6 $ 394.3 $ 385.1 $ 360.6