Bank Credit Facility (Details) - USD ($) $ in Millions	1 Months Ended
	Aug. 31, 2018	May 30, 2015	Nov. 03, 2018	May 28, 2015
2011 Credit Agreement [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				$ 700.0
Debt Instrument, Term		5 years
2018 Credit Agreement [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 700.0
Debt Instrument, Term	5 years
Deferred Finance Costs, Gross	$ 1.5
Line of Credit Facility, Swing Loan Sublimit	30.0
Line of Credit Facility, Letter of Credit Sublimit	75.0
Line of Credit Facility, Foreign Borrower Sublimit	75.0
Line of Credit Facility, Optional Currency Sublimit	$ 200.0
Line of Credit Facility, Amount Outstanding			$ 488.0
Line of Credit Facility, Letters of Credit Outstanding			8.6
Line of Credit Facility, Remaining Borrowing Capacity			$ 203.4