Financing Arrangements (Details) - USD ($)	Oct. 11, 2016	Sep. 22, 2016	Dec. 31, 2017	Oct. 25, 2017	Aug. 18, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Fair value adjustment related to hedged fixed rate debt			$ 1,000,000			$ 3,000,000
Long-term debt			1,744,000,000			1,850,000,000
Short-term borrowings			120,000,000			106,000,000
Long-term Debt, Total			$ 1,864,000,000			$ 1,956,000,000
Line of credit facility, maximum borrowing capacity		$ 1,000,000,000
Senior Notes 3.2 Percent Due October 1, 2026
Debt Instrument [Line Items]
Debt, interest rate (as a percent)		3.20%	3.20%			3.20%
Aggregate principal Amount		$ 500,000,000
Long-term debt			$ 496,000,000			$ 496,000,000
Net proceeds from sale of the notes		497,000,000
Term loan credit agreement due April 25, 2019
Debt Instrument [Line Items]
Long-term debt			$ 395,000,000
Repayments of Long-term Debt		350,000,000
Senior Notes 4.625 Percent Due November 1, 2020
Debt Instrument [Line Items]
Debt, interest rate (as a percent)			4.625%			4.625%
Aggregate principal Amount			$ 400,000,000
Long-term debt			$ 398,000,000			$ 398,000,000
Senior Notes 1.8 Percent Due September 25, 2017
Debt Instrument [Line Items]
Debt, interest rate (as a percent)			1.80%			1.80%
Long-term debt						$ 299,000,000
Senior Notes 6.0 Percent Due April 15, 2017
Debt Instrument [Line Items]
Debt, interest rate (as a percent)			6.00%			6.00%
Long-term debt						$ 200,000,000
Senior Notes 5.62 Percent Due March 25, 2020
Debt Instrument [Line Items]
Debt, interest rate (as a percent)			5.62%			5.62%
Long-term debt			$ 200,000,000			$ 200,000,000
Term loan credit agreement
Debt Instrument [Line Items]
Aggregate principal Amount				$ 420,000,000
Line of credit facility, maximum borrowing capacity					$ 500,000,000
Revolving Credit Agreement
Debt Instrument [Line Items]
Payment of borrowings under revolving credit facility		$ 52,000,000
Borrowings outstanding			$ 0
Line of credit facility, maximum borrowing capacity	$ 1,000,000,000
Debt Instrument, Term	5 years