Financial Instruments - Derivatives (Details) € in Millions, ₩ in Millions, ¥ in Millions, ¥ in Millions, £ in Millions, zł in Millions, kr in Millions, $ in Millions, $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2019 PLN (zł) t	Dec. 31, 2018 PLN (zł) t	Sep. 30, 2019 KRW (₩)	Sep. 30, 2019 USD ($)	Sep. 30, 2019 JPY (¥)	Sep. 30, 2019 MXN ($)	Sep. 30, 2019 CNY (¥)	Sep. 30, 2019 SEK (kr)	Sep. 30, 2019 EUR (€)	Sep. 30, 2019 GBP (£)	Dec. 31, 2018 KRW (₩)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 JPY (¥)	Dec. 31, 2018 MXN ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2018 SEK (kr)	Dec. 31, 2018 EUR (€)	Dec. 31, 2018 GBP (£)
Commodity contracts | Maturity December 2020
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass | t	261	257
Brazil, Brazil Real | Foreign currency | Maturity December 2019
Derivative [Line Items]
Derivative, Notional Amount				$ 2								$ 5
Brazil, Brazil Real | Foreign currency | Maturity January 2020
Derivative [Line Items]
Derivative, Notional Amount | €									€ 2								€ 4
United Kingdom, Pounds | Foreign currency | Maturity March 2020
Derivative [Line Items]
Derivative, Notional Amount				6					17			0					0
China, Yuan Renminbi | Foreign currency | Maturity December 2019
Derivative [Line Items]
Derivative, Notional Amount				10								0
Euro Member Countries, Euro | Cross Currency Interest Rate Contract [Member] | Maturity September 2020
Derivative [Line Items]
Derivative, Notional Amount | €									206
Euro Member Countries, Euro | Foreign currency | Maturity December 2019
Derivative [Line Items]
Derivative, Notional Amount	zł 7.0	zł 0.0			¥ 131		¥ 11			£ 1			¥ 0		¥ 0			£ 7
Euro Member Countries, Euro | Foreign currency | Maturity June 2020
Derivative [Line Items]
Derivative, Notional Amount | kr								kr 540								kr 540
Euro Member Countries, Euro | Foreign currency | Maturity December 2020
Derivative [Line Items]
Derivative, Notional Amount				9								19
Japan, Yen | Cross Currency Interest Rate Contract [Member] | Maturity February 2023
Derivative [Line Items]
Derivative, Notional Amount | ¥					10,978
Japan, Yen | Foreign currency | Maturity December 2019
Derivative [Line Items]
Derivative, Notional Amount			₩ 1,359.0	1			¥ 23				₩ 5,785.0	3			¥ 89
Korea (South), Won | Foreign currency | Maturity December 2019
Derivative [Line Items]
Derivative, Notional Amount				7	54				2			$ 7	266				6
Sweden, Kronor | Foreign currency | Maturity January 2020
Derivative [Line Items]
Derivative, Notional Amount | €									17								56
United States of America, Dollars | Cross Currency Interest Rate Contract [Member] | Maturity September 2020
Derivative [Line Items]
Derivative, Notional Amount				250
United States of America, Dollars | Cross Currency Interest Rate Contract [Member] | Maturity February 2023
Derivative [Line Items]
Derivative, Notional Amount				$ 100
United States of America, Dollars | Foreign currency | Maturity December 2019
Derivative [Line Items]
Derivative, Notional Amount			₩ 36,721.0		¥ 1,900	$ 153					₩ 0.0		¥ 0	$ 575
United States of America, Dollars | Foreign currency | Maturity January 2020
Derivative [Line Items]
Derivative, Notional Amount | €									€ 14								€ 0