Fair Value Measurements - Assets and Liabilities Measured at Fair Value (Detail) - USD ($)		Jun. 30, 2017	Sep. 30, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		$ 95,000,000	$ 95,000,000
Derivative liabilities		1,713,000,000	2,980,000,000
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		463,000,000	443,000,000
Total liabilities		1,713,000,000	2,980,000,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		427,000,000	348,000,000
Total liabilities		1,693,000,000	2,057,000,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		36,000,000	95,000,000
Total liabilities		20,000,000	923,000,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		0	0
Total liabilities		0	0
Other Current Assets | Fair Value, Measurements, Recurring [Member] | Exchange Traded Funds in Fixed Income securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	[1]	14,000,000	15,000,000
Other Current Assets | Fair Value, Measurements, Recurring [Member] | Exchange Traded Funds in Fixed Income securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	[1]	14,000,000	15,000,000
Other Current Assets | Fair Value, Measurements, Recurring [Member] | Exchange Traded Funds in Fixed Income securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	[1]	0	0
Other Current Assets | Fair Value, Measurements, Recurring [Member] | Exchange Traded Funds in Fixed Income securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	[1]	0	0
Other Current Assets | Fair Value, Measurements, Recurring [Member] | Foreign Currency Exchange Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		33,000,000	90,000,000
Other Current Assets | Fair Value, Measurements, Recurring [Member] | Foreign Currency Exchange Derivatives | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Other Current Assets | Fair Value, Measurements, Recurring [Member] | Foreign Currency Exchange Derivatives | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		33,000,000	90,000,000
Other Current Assets | Fair Value, Measurements, Recurring [Member] | Foreign Currency Exchange Derivatives | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Other Current Assets | Fair Value, Measurements, Recurring [Member] | Commodity Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		3,000,000	4,000,000
Other Current Assets | Fair Value, Measurements, Recurring [Member] | Commodity Derivatives | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Other Current Assets | Fair Value, Measurements, Recurring [Member] | Commodity Derivatives | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		3,000,000	4,000,000
Other Current Assets | Fair Value, Measurements, Recurring [Member] | Commodity Derivatives | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Other Noncurrent Assets | Fair Value, Measurements, Recurring [Member] | Available-for-sale Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		15,000,000	3,000,000
Other Noncurrent Assets | Fair Value, Measurements, Recurring [Member] | Available-for-sale Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		15,000,000	3,000,000
Other Noncurrent Assets | Fair Value, Measurements, Recurring [Member] | Available-for-sale Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		0	0
Other Noncurrent Assets | Fair Value, Measurements, Recurring [Member] | Available-for-sale Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		0	0
Other Noncurrent Assets | Fair Value, Measurements, Recurring [Member] | Deferred compensation plan assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		89,000,000	81,000,000
Other Noncurrent Assets | Fair Value, Measurements, Recurring [Member] | Deferred compensation plan assets [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		89,000,000	81,000,000
Other Noncurrent Assets | Fair Value, Measurements, Recurring [Member] | Deferred compensation plan assets [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		0	0
Other Noncurrent Assets | Fair Value, Measurements, Recurring [Member] | Deferred compensation plan assets [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		0	0
Other Noncurrent Assets | Fair Value, Measurements, Recurring [Member] | Exchange Traded Funds in Fixed Income securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	[1]	154,000,000	163,000,000
Other Noncurrent Assets | Fair Value, Measurements, Recurring [Member] | Exchange Traded Funds in Fixed Income securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	[1]	154,000,000	163,000,000
Other Noncurrent Assets | Fair Value, Measurements, Recurring [Member] | Exchange Traded Funds in Fixed Income securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	[1]	0	0
Other Noncurrent Assets | Fair Value, Measurements, Recurring [Member] | Exchange Traded Funds in Fixed Income securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	[1]	0	0
Other Noncurrent Assets | Fair Value, Measurements, Recurring [Member] | Exchange traded funds in equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	[1]	96,000,000	86,000,000
Other Noncurrent Assets | Fair Value, Measurements, Recurring [Member] | Exchange traded funds in equity securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	[1]	96,000,000	86,000,000
Other Noncurrent Assets | Fair Value, Measurements, Recurring [Member] | Exchange traded funds in equity securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	[1]	0	0
Other Noncurrent Assets | Fair Value, Measurements, Recurring [Member] | Exchange traded funds in equity securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	[1]	0	0
Other Noncurrent Assets | Fair Value, Measurements, Recurring [Member] | Equity swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		59,000,000
Other Noncurrent Assets | Fair Value, Measurements, Recurring [Member] | Equity swap | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		59,000,000
Other Noncurrent Assets | Fair Value, Measurements, Recurring [Member] | Equity swap | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		0
Other Noncurrent Assets | Fair Value, Measurements, Recurring [Member] | Equity swap | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure		0
Other Noncurrent Assets | Fair Value, Measurements, Recurring [Member] | Interest Rate Swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets			1,000,000
Other Noncurrent Assets | Fair Value, Measurements, Recurring [Member] | Interest Rate Swaps | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets			0
Other Noncurrent Assets | Fair Value, Measurements, Recurring [Member] | Interest Rate Swaps | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets			1,000,000
Other Noncurrent Assets | Fair Value, Measurements, Recurring [Member] | Interest Rate Swaps | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets			0
Other Current Liabilities | Fair Value, Measurements, Recurring [Member] | Foreign Currency Exchange Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		19,000,000	66,000,000
Other Current Liabilities | Fair Value, Measurements, Recurring [Member] | Foreign Currency Exchange Derivatives | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		0	0
Other Current Liabilities | Fair Value, Measurements, Recurring [Member] | Foreign Currency Exchange Derivatives | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		19,000,000	66,000,000
Other Current Liabilities | Fair Value, Measurements, Recurring [Member] | Foreign Currency Exchange Derivatives | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		0	0
Other Current Liabilities | Fair Value, Measurements, Recurring [Member] | Commodity Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		1,000,000
Other Current Liabilities | Fair Value, Measurements, Recurring [Member] | Commodity Derivatives | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		0
Other Current Liabilities | Fair Value, Measurements, Recurring [Member] | Commodity Derivatives | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		1,000,000
Other Current Liabilities | Fair Value, Measurements, Recurring [Member] | Commodity Derivatives | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		0
Liabilities held for sale [Domain] | Fair Value, Measurements, Recurring [Member] | Foreign Currency Exchange Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities			5,000,000
Liabilities held for sale [Domain] | Fair Value, Measurements, Recurring [Member] | Foreign Currency Exchange Derivatives | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities			0
Liabilities held for sale [Domain] | Fair Value, Measurements, Recurring [Member] | Foreign Currency Exchange Derivatives | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities			5,000,000
Liabilities held for sale [Domain] | Fair Value, Measurements, Recurring [Member] | Foreign Currency Exchange Derivatives | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities			0
Current Portion of Long-Term Debt | Fair Value, Measurements, Recurring [Member] | Fixed Rate Debt Swapped to Floating
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities			551,000,000
Current Portion of Long-Term Debt | Fair Value, Measurements, Recurring [Member] | Fixed Rate Debt Swapped to Floating | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities			0
Current Portion of Long-Term Debt | Fair Value, Measurements, Recurring [Member] | Fixed Rate Debt Swapped to Floating | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities			551,000,000
Current Portion of Long-Term Debt | Fair Value, Measurements, Recurring [Member] | Fixed Rate Debt Swapped to Floating | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities			0
Long-term Debt | Fair Value, Measurements, Recurring [Member] | Fixed Rate Debt Swapped to Floating
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities			301,000,000
Long-term Debt | Fair Value, Measurements, Recurring [Member] | Fixed Rate Debt Swapped to Floating | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities			0
Long-term Debt | Fair Value, Measurements, Recurring [Member] | Fixed Rate Debt Swapped to Floating | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities			301,000,000
Long-term Debt | Fair Value, Measurements, Recurring [Member] | Fixed Rate Debt Swapped to Floating | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities			0
Long-term Debt | Fair Value, Measurements, Recurring [Member] | Foreign Currency Denominated Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		1,693,000,000	938,000,000
Long-term Debt | Fair Value, Measurements, Recurring [Member] | Foreign Currency Denominated Debt [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		1,693,000,000	938,000,000
Long-term Debt | Fair Value, Measurements, Recurring [Member] | Foreign Currency Denominated Debt [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		0	0
Long-term Debt | Fair Value, Measurements, Recurring [Member] | Foreign Currency Denominated Debt [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		$ 0	0
Noncurrent liabilities held for sale [Domain] | Fair Value, Measurements, Recurring [Member] | Foreign Currency Exchange Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities			1,119,000,000
Noncurrent liabilities held for sale [Domain] | Fair Value, Measurements, Recurring [Member] | Foreign Currency Exchange Derivatives | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities			1,119,000,000
Noncurrent liabilities held for sale [Domain] | Fair Value, Measurements, Recurring [Member] | Foreign Currency Exchange Derivatives | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities			0
Noncurrent liabilities held for sale [Domain] | Fair Value, Measurements, Recurring [Member] | Foreign Currency Exchange Derivatives | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities			$ 0

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