Fair Value Measurements Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Millions		Sep. 30, 2018	Sep. 30, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		$ 80	$ 91
Gross amount, derivative liabilities		3,175	2,105
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		465	462
Total liabilities		26	47
Exchange traded funds in equity securities [Member] | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets	[1]		55
Investments in marketable common stock	[1]	119
Deferred compensation plan assets [Member] | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock		100	155
Foreign currency exchange derivatives | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		16	27
Foreign currency exchange derivatives | Other current liabilities | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities		12	46
Foreign currency exchange derivatives | Liabilities held for sale [Domain] | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities			1
Exchange Traded Funds in Fixed Income securities [Member] | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets	[1]	14	14
Exchange Traded Funds in Fixed Income securities [Member] | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock	[1]	148	100
Commodity derivatives | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		1	9
Commodity derivatives | Other current liabilities | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities		14
Interest rate swaps | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock			10
Available-for-sale Securities [Member] | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock		4	92
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		385	371
Total liabilities		0	0
Fair Value, Inputs, Level 1 | Exchange traded funds in equity securities [Member] | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets	[1]		0
Investments in marketable common stock	[1]	119
Fair Value, Inputs, Level 1 | Deferred compensation plan assets [Member] | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock		100
Fair Value, Inputs, Level 1 | Foreign currency exchange derivatives | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		0	0
Fair Value, Inputs, Level 1 | Foreign currency exchange derivatives | Other current liabilities | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities		0	0
Fair Value, Inputs, Level 1 | Foreign currency exchange derivatives | Liabilities held for sale [Domain] | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities			0
Fair Value, Inputs, Level 1 | Exchange Traded Funds in Fixed Income securities [Member] | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets	[1]	14	14
Fair Value, Inputs, Level 1 | Exchange Traded Funds in Fixed Income securities [Member] | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock	[1]	148	100
Fair Value, Inputs, Level 1 | Commodity derivatives | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		0	0
Fair Value, Inputs, Level 1 | Commodity derivatives | Other current liabilities | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities		0
Fair Value, Inputs, Level 1 | Interest rate swaps | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock			10
Fair Value, Inputs, Level 1 | Available-for-sale Securities [Member] | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock		4	92
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		80	91
Total liabilities		26	47
Significant Other Observable Inputs (Level 2) | Exchange traded funds in equity securities [Member] | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets	[1]		55
Investments in marketable common stock	[1]	0
Significant Other Observable Inputs (Level 2) | Deferred compensation plan assets [Member] | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock		0	0
Significant Other Observable Inputs (Level 2) | Foreign currency exchange derivatives | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		16	27
Significant Other Observable Inputs (Level 2) | Foreign currency exchange derivatives | Other current liabilities | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities		12	46
Significant Other Observable Inputs (Level 2) | Foreign currency exchange derivatives | Liabilities held for sale [Domain] | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities			1
Significant Other Observable Inputs (Level 2) | Exchange Traded Funds in Fixed Income securities [Member] | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets	[1]	0	0
Significant Other Observable Inputs (Level 2) | Exchange Traded Funds in Fixed Income securities [Member] | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock	[1]	0	0
Significant Other Observable Inputs (Level 2) | Commodity derivatives | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		1	9
Significant Other Observable Inputs (Level 2) | Commodity derivatives | Other current liabilities | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities		14
Significant Other Observable Inputs (Level 2) | Interest rate swaps | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock			0
Significant Other Observable Inputs (Level 2) | Available-for-sale Securities [Member] | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock		0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		0	0
Total liabilities		0	0
Significant Unobservable Inputs (Level 3) | Exchange traded funds in equity securities [Member] | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets	[1]		0
Investments in marketable common stock	[1]	0
Significant Unobservable Inputs (Level 3) | Deferred compensation plan assets [Member] | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock		0	0
Significant Unobservable Inputs (Level 3) | Foreign currency exchange derivatives | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		0	0
Significant Unobservable Inputs (Level 3) | Foreign currency exchange derivatives | Other current liabilities | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities		0	0
Significant Unobservable Inputs (Level 3) | Foreign currency exchange derivatives | Liabilities held for sale [Domain] | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities			0
Significant Unobservable Inputs (Level 3) | Exchange Traded Funds in Fixed Income securities [Member] | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets	[1]	0	0
Significant Unobservable Inputs (Level 3) | Exchange Traded Funds in Fixed Income securities [Member] | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock	[1]	0	0
Significant Unobservable Inputs (Level 3) | Commodity derivatives | Other current assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount recognized, derivative assets		0	0
Significant Unobservable Inputs (Level 3) | Commodity derivatives | Other current liabilities | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross amount, derivative liabilities		0
Significant Unobservable Inputs (Level 3) | Interest rate swaps | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock			0
Significant Unobservable Inputs (Level 3) | Available-for-sale Securities [Member] | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock		0	$ 0
Equity swap | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock		63
Equity swap | Fair Value, Inputs, Level 1 | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock		0
Equity swap | Significant Other Observable Inputs (Level 2) | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock		63
Equity swap | Significant Unobservable Inputs (Level 3) | Other noncurrent assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock		$ 0

[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.