Financing Components of Debt (Details) - USD ($)	Dec. 31, 2016	Jun. 20, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Long-term borrowings, carrying value	$ 3,358,000,000		$ 0
Commercial Paper [Member]
Debt Instrument [Line Items]
Long-term borrowings, carrying value	374,800,000
US Dollar-Denominated Commercial Paper [Member] | Commercial Paper [Member]
Debt Instrument [Line Items]
Long-term borrowings, carrying value	347,900,000
Euro Denominated Commercial Paper [Member] | Commercial Paper [Member]
Debt Instrument [Line Items]
Long-term borrowings, carrying value	26,800,000
Senior Unsecured Notes due 2019 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Long-term borrowings, carrying value	298,300,000
Interest rate		1.80%
Senior Unsecured Notes due 2021 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Long-term borrowings, carrying value	744,800,000
Interest rate		2.35%
Senior Unsecured Notes due 2026 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Long-term borrowings, carrying value	890,100,000
Interest rate		3.15%
Senior Unsecured Notes due 2046 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Long-term borrowings, carrying value	546,800,000
Interest rate		4.30%
Other Debt [Member]
Debt Instrument [Line Items]
Long-term borrowings, carrying value	3,300,000
Term Loan
Debt Instrument [Line Items]
Long-term borrowings, carrying value	$ 500,000,000	$ 500,000,000
Interest rate	1.87%