Debt (Schedule of Long-term Debt) (Details) € in Millions, $ in Millions		12 Months Ended
		Dec. 31, 2019 USD ($)	May 08, 2019 USD ($)	Dec. 31, 2018 USD ($)	Nov. 05, 2018 EUR (€)
Long-Term Debt
Finance Lease, Liability		$ 144		$ 167
Subtotal		3,455		3,355
Current installments of long-term debt		(28)		(367)
Total		$ 3,409		2,970
Debt Instrument, Redemption Price, Percentage		100.00%
Senior Unsecured Notes Due 2024 [Member]
Long-Term Debt
Senior unsecured notes		$ 841		857
Maturity Date		May 08, 2024
Interest Rate		3.50%
Long-term Debt, Gross			$ 500
Percentage of Face			99.895%
Senior Unsecured Term Loan Due 2021 [Member]
Long-Term Debt
Maturity Date		Jul. 15, 2021
Senior Unsecured Notes Due 2019 [Member]
Long-Term Debt
Senior unsecured notes		$ 0		343
Maturity Date		Oct. 15, 2019
Interest Rate		3.25%
Senior Unsecured Notes Due 2021 [Member]
Long-Term Debt
Senior unsecured notes		$ 400		400
Maturity Date		Jun. 15, 2021
Interest Rate		5.875%
Senior Unsecured Notes Due 2022 [Member]
Long-Term Debt
Senior unsecured notes		$ 500		500
Maturity Date		Nov. 15, 2022
Interest Rate		4.625%
Senior Unsecured Notes Due 2023 [Member]
Long-Term Debt
Senior unsecured notes		$ 499		0
Maturity Date		Sep. 26, 2023
Interest Rate		1.125%
Senior Unsecured Notes Due 2025 [Member]
Long-Term Debt
Senior unsecured notes		$ 337		343
Maturity Date		Dec. 11, 2025
Interest Rate		1.25%
Senior Unsecured Notes Due 2027 [Member]
Long-Term Debt
Senior unsecured notes		$ 558		568
Maturity Date		Mar. 01, 2027
Interest Rate		2.125%
Long-term Debt, Gross | €					€ 500
Percentage of Face					99.231%
Pollution control and industrial revenue bonds due at various dates through 2030, interest rates ranging from 4.05% to 5.00% [Member]
Long-Term Debt
Other Long-term debt		$ 167		$ 167
Year of maturity, range end		Nov. 01, 2030
Refunding loan for pollution control and industrial revenue bonds [Member]
Long-Term Debt
Year of maturity, range end		Dec. 31, 2030
Nilit bank loans due at various dates through 2026 (Note 4) [Member]
Debt Instrument [Line Items]
Long-term Debt, Weighted Average Interest Rate, at Point in Time		1.30%		1.30%
Long-Term Debt
Other Long-term debt	[1]	$ 9		$ 10
Year of maturity, range end		Dec. 31, 2026
Obligations Under Capital Leases [Member]
Long-Term Debt
Year of maturity, range end		Mar. 31, 2054
Long-term Debt [Member]
Long-Term Debt
Unamortized debt issuance costs	[2]	$ (18)		$ (18)
Minimum [Member] | Pollution control and industrial revenue bonds due at various dates through 2030, interest rates ranging from 4.05% to 5.00% [Member]
Long-Term Debt
Interest Rate		5.70%
Minimum [Member] | Refunding loan for pollution control and industrial revenue bonds [Member]
Long-Term Debt
Interest Rate		4.05%
Maximum [Member] | Pollution control and industrial revenue bonds due at various dates through 2030, interest rates ranging from 4.05% to 5.00% [Member]
Long-Term Debt
Interest Rate		6.70%
Maximum [Member] | Refunding loan for pollution control and industrial revenue bonds [Member]
Long-Term Debt
Interest Rate		5.00%

[1] The weighted average interest rate was 1.3% and 1.3% as of December 31, 2019 and 2018, respectively.

[2] Related to the Company's long-term debt, excluding obligations under finance leases.