Annual report pursuant to Section 13 and 15(d)

Income Taxes (Narrative) (Details)

v3.7.0.1
Income Taxes (Narrative) (Details) - USD ($)
$ in Millions
 1 Months Ended 12 Months Ended
Dec. 31, 2016
May 31, 2017
May 31, 2016
Income Tax Contingency [Line Items]      
Reserve for uncertain tax positions   $ 39.2 $ 54.2
Decreased reserve for uncertain tax positions $ 28.9    
Impact of uncertain tax positions, if recognized, on effective income tax rate   $ 39.2 $ 54.2
IRS [Member] | Earliest Tax Year [Member]      
Income Tax Contingency [Line Items]      
Fiscal year currently under audit   2012  
Fiscal years subject to potential audit   2015  
IRS [Member] | Latest Tax Year [Member]      
Income Tax Contingency [Line Items]      
Fiscal year currently under audit   2014  
Fiscal years subject to potential audit   2017