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Borrowings and Lines of Credit (Long-term Debt Obligations) (Details) € in Millions, $ in Millions	1 Months Ended	2 Months Ended	12 Months Ended
	Jan. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 EUR (€)	Dec. 31, 2017 USD ($)	Dec. 31, 2017 EUR (€)	Dec. 31, 2016 USD ($)	Dec. 31, 2016 EUR (€)	Feb. 28, 2018 USD ($)
Debt Instrument [Line Items]
Long-term debt			$ 5,000		$ 4,123
Capital lease obligations			12		15
Long-term debt and capital lease obligations			5,012		4,138
Less payments due within one year			647		4
Long-term debt			4,365		$ 4,134
Effective interest rates					8.40%
Repayments of debt			$ 6		$ 588		$ 379
Proceeds from notes payable		$ 987
Notes 6.65 Percent Due 2018
Debt Instrument [Line Items]
Long-term debt		$ 125					125
Repayments of debt							$ 133
Debt instrument, interest rate, stated percentage		6.65%	6.65%				6.65%
Notes 0.00% Due 2019
Debt Instrument [Line Items]
Long-term debt			$ 343		358
Notional amount of non-derivative instruments \| €								€ 300
Debt instrument, interest rate, stated percentage		0.00%					0.00%
Notes 2.3 Percent Due 2019
Debt Instrument [Line Items]
Long-term debt			$ 299		299
Debt instrument, interest rate, stated percentage			2.30%
3-year Variable Rate Euro Bank Loan Due 2017
Debt Instrument [Line Items]
Repayments of debt					587
Notional amount of non-derivative instruments \| €						€ 500
Notes 3.6 Percent Due 2020
Debt Instrument [Line Items]
Long-term debt			$ 498		497
Debt instrument, interest rate, stated percentage			3.60%
Non-callable Debentures 9 Percent Due 2021
Debt Instrument [Line Items]
Long-term debt			$ 133		133
Debt instrument, interest rate, stated percentage			9.00%
Notes 0.875 Percent Due 2022
Debt Instrument [Line Items]
Long-term debt			$ 685		716
Notional amount of non-derivative instruments \| €				€ 600
Debt instrument, interest rate, stated percentage			0.875%
3.2% Notes due 2023
Debt Instrument [Line Items]
Long-term debt			$ 298		0
Effective interest rates			2.70%
Interest rate swaps									$ 150
Notional amount of non-derivative instruments			$ 300
Debt instrument, interest rate, stated percentage			3.20%
Notes 0.875% Due 2025
Debt Instrument [Line Items]
Long-term debt			$ 679		710
Notional amount of non-derivative instruments \| €								€ 600
Debt instrument, interest rate, stated percentage		0.875%					0.875%
Notes 1.4 Percent Due 2027
Debt Instrument [Line Items]
Long-term debt			$ 679		711
Debt instrument, interest rate, stated percentage			1.40%
3.75% Notes due 2028
Debt Instrument [Line Items]
Long-term debt			$ 694		0
Effective interest rates									3.20%
Interest rate swaps									$ 375
Notional amount of non-derivative instruments			$ 700
Debt instrument, interest rate, stated percentage			3.75%
Notes 2.5 Percent Due 2029
Debt Instrument [Line Items]
Long-term debt			$ 91		95
Notional amount of non-derivative instruments \| €				80
Debt instrument, interest rate, stated percentage			2.50%
Notes 7.70 Percent Due 2038
Debt Instrument [Line Items]
Long-term debt			$ 174		174
Debt instrument, interest rate, stated percentage			7.70%
Notes 5.5 Percent Due 2040
Debt Instrument [Line Items]
Long-term debt			$ 247		247
Debt instrument, interest rate, stated percentage			5.50%
Notes 3.0 Percent Due 2044
Debt Instrument [Line Items]
Long-term debt			$ 131		137
Notional amount of non-derivative instruments \| €				€ 120
Debt instrument, interest rate, stated percentage			3.00%
Other Non US Debt
Debt Instrument [Line Items]
Long-term debt			$ 39		$ 43
Long-term debt, percentage bearing variable interest, percentage rate			3.80%		3.70%
Impact Of Derivatives On Debt
Debt Instrument [Line Items]
Long-term debt			$ 10		$ 3
Term Loan Credit Agreements 2016
Debt Instrument [Line Items]
Repayments of debt							$ 250
Notes 1.9 Percent Due 2016
Debt Instrument [Line Items]
Notional amount of non-derivative instruments	$ 250
Debt instrument, interest rate, stated percentage	1.90%		1.90%