Fair Value Measurements (Major Categories of Financial Assets and Liabilities Measured on a Recurring Basis) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Sep. 09, 2020	Dec. 31, 2019
Other Current Assets [Member]
Other assets	$ 132		$ 157
Contingent consideration		$ 24
Other Current Assets [Member] | Significant Other Observable Inputs (Level 2) [Member]
Other assets	104		157
Other Current Assets [Member] | Significant Unobservable Inputs (Level 3) [Member]
Other assets	28
Other Assets [Member]
Contingent consideration		$ 20
Other Noncurrent Assets [Member]
Investments	13
Other assets	95		92
Other Noncurrent Assets [Member] | Quoted Market Prices in Active Markets for Identical Assets (Level 1) [Member]
Investments	13
Other Noncurrent Assets [Member] | Significant Other Observable Inputs (Level 2) [Member]
Other assets	79		71
Other Noncurrent Assets [Member] | Significant Unobservable Inputs (Level 3) [Member]
Other assets	16		21
Other Accrued Liabilities [Member]
Other accrued liabilities	143		100
Other Accrued Liabilities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Other accrued liabilities	143		100
Other Liabilities [Member]
Other liabilities	131		165
Other Liabilities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Other liabilities	$ 131		165
Renewable Energy [Member] | Other Noncurrent Assets [Member]
Other assets			$ 21