Fair Value Measurements Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Millions		Sep. 30, 2020	Sep. 30, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		$ 87	$ 97
Gross amount, derivative liabilities		3,020	2,568
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		441	441
Total liabilities		10	24
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		354	344
Total liabilities		0	0
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		87	97
Total liabilities		10	24
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		0	0
Total liabilities		0	0
Fair Value, Measurements, Recurring | Other noncurrent assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred Compensation Plan Assets		63	71
Fair Value, Measurements, Recurring | Other noncurrent assets | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred Compensation Plan Assets		63	71
Fair Value, Measurements, Recurring | Other noncurrent assets | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred Compensation Plan Assets		0	0
Fair Value, Measurements, Recurring | Other noncurrent assets | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred Compensation Plan Assets		0	0
Fair Value, Measurements, Recurring | Fixed Income Securities [Member] | Other current assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock	[1]	19	19
Fair Value, Measurements, Recurring | Fixed Income Securities [Member] | Other current assets | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock	[1]	19	19
Fair Value, Measurements, Recurring | Fixed Income Securities [Member] | Other current assets | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock	[1]	0	0
Fair Value, Measurements, Recurring | Fixed Income Securities [Member] | Other current assets | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock	[1]	0	0
Fair Value, Measurements, Recurring | Fixed Income Securities [Member] | Other noncurrent assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock	[1]	143	138
Fair Value, Measurements, Recurring | Fixed Income Securities [Member] | Other noncurrent assets | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock	[1]	143	138
Fair Value, Measurements, Recurring | Fixed Income Securities [Member] | Other noncurrent assets | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock	[1]	0	0
Fair Value, Measurements, Recurring | Fixed Income Securities [Member] | Other noncurrent assets | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock	[1]	0	0
Fair Value, Measurements, Recurring | Equity Securities [Member] | Other noncurrent assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock	[1]	129	116
Fair Value, Measurements, Recurring | Equity Securities [Member] | Other noncurrent assets | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock	[1]	129	116
Fair Value, Measurements, Recurring | Equity Securities [Member] | Other noncurrent assets | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock	[1]	0	0
Fair Value, Measurements, Recurring | Equity Securities [Member] | Other noncurrent assets | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock	[1]	0	0
Fair Value, Measurements, Recurring | Foreign currency exchange derivatives | Other current assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		27	35
Fair Value, Measurements, Recurring | Foreign currency exchange derivatives | Other current assets | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		0	0
Fair Value, Measurements, Recurring | Foreign currency exchange derivatives | Other current assets | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		27	35
Fair Value, Measurements, Recurring | Foreign currency exchange derivatives | Other current assets | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		0	0
Fair Value, Measurements, Recurring | Foreign currency exchange derivatives | Other current liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities		10	23
Fair Value, Measurements, Recurring | Foreign currency exchange derivatives | Other current liabilities | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities		0	0
Fair Value, Measurements, Recurring | Foreign currency exchange derivatives | Other current liabilities | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities		10	23
Fair Value, Measurements, Recurring | Foreign currency exchange derivatives | Other current liabilities | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities		0	0
Fair Value, Measurements, Recurring | Commodity derivatives | Other current liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities		2	1
Fair Value, Measurements, Recurring | Commodity derivatives | Other current liabilities | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities		0	0
Fair Value, Measurements, Recurring | Commodity derivatives | Other current liabilities | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities		2	1
Fair Value, Measurements, Recurring | Commodity derivatives | Other current liabilities | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities		0	0
Fair Value, Measurements, Recurring | Equity swap | Other noncurrent assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		58	62	[1]
Fair Value, Measurements, Recurring | Equity swap | Other noncurrent assets | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		0	0	[1]
Fair Value, Measurements, Recurring | Equity swap | Other noncurrent assets | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		58	62	[1]
Fair Value, Measurements, Recurring | Equity swap | Other noncurrent assets | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		$ 0	$ 0	[1]

[1]  1Classified as restricted investments for payment of asbestos liabilities. See Note 22, "Commitments and Contingencies" of the notes to consolidated financial statements for further details.