Fair Value Measurements - Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Millions	Sep. 30, 2023	Sep. 30, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	$ 56	$ 54
Total liabilities	3,280	3,138
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	332	339
Total liabilities	151	121
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	276	285
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	56	54
Total liabilities	27	61
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	124	60
Fair Value, Measurements, Recurring | Other noncurrent assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred compensation plan assets	45	46
Fair Value, Measurements, Recurring | Other noncurrent assets | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred compensation plan assets	45	46
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 | Other current liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent earn-out liabilities	48	30
Fair Value, Measurements, Recurring | Other current liabilities | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent earn-out liabilities	0	0
Fair Value, Measurements, Recurring | Other current liabilities | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent earn-out liabilities	0	0
Fair Value, Measurements, Recurring | Other current liabilities | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent earn-out liabilities	48	30
Fair Value, Measurements, Recurring | Other noncurrent liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent earn-out liabilities	76	30
Fair Value, Measurements, Recurring | Other noncurrent liabilities | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent earn-out liabilities	0	0
Fair Value, Measurements, Recurring | Other noncurrent liabilities | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent earn-out liabilities	0	0
Fair Value, Measurements, Recurring | Other noncurrent liabilities | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent earn-out liabilities	76	30
Fair Value, Measurements, Recurring | Fixed Income Securities | Other current assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock		22
Fair Value, Measurements, Recurring | Fixed Income Securities | Other current assets | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock		22
Fair Value, Measurements, Recurring | Fixed Income Securities | 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		0
Fair Value, Measurements, Recurring | Fixed Income Securities | 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		0
Fair Value, Measurements, Recurring | Fixed Income Securities | Other noncurrent assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock	76	86
Fair Value, Measurements, Recurring | Fixed Income Securities | Other noncurrent assets | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock	76	86
Fair Value, Measurements, Recurring | Fixed Income Securities | 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	0	0
Fair Value, Measurements, Recurring | Fixed Income Securities | 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	0	0
Fair Value, Measurements, Recurring | Equity Securities | Other noncurrent assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock	155	131
Fair Value, Measurements, Recurring | Equity Securities | Other noncurrent assets | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable common stock	155	131
Fair Value, Measurements, Recurring | Equity Securities | 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	0	0
Fair Value, Measurements, Recurring | Equity Securities | 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	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]
Derivative assets	29	54
Fair Value, Measurements, Recurring | Foreign currency exchange derivatives | Other current assets | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
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]
Derivative assets	29	54
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]
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]
Total liabilities	25	51
Fair Value, Measurements, Recurring | Foreign currency exchange derivatives | Other current liabilities | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total 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]
Total liabilities	25	51
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]
Total 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]
Derivative assets	5
Fair Value, Measurements, Recurring | Equity swap | Other noncurrent assets | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0
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]
Derivative assets	5
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]
Derivative assets	0
Fair Value, Measurements, Recurring | Commodity derivatives | Other current liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities	2	10
Fair Value, Measurements, Recurring | Commodity derivatives | Other current liabilities | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total 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]
Total liabilities	2	10
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]
Total liabilities	0	$ 0
Fair Value, Measurements, Recurring | Interest rate swaps | Other current assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	22
Fair Value, Measurements, Recurring | Interest rate swaps | Other current assets | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0
Fair Value, Measurements, Recurring | Interest rate swaps | Other current assets | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	22
Fair Value, Measurements, Recurring | Interest rate swaps | Other current assets | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	$ 0