Income Taxes - Additional Information (Detail) - USD ($) $ in Millions		3 Months Ended		12 Months Ended
	Jan. 01, 2018	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Income Taxes [Line Items]
Net tax expense from impact of Tax Cuts and Job Act of 2017				$ 159
Net tax expense upon sale of assets				3
Net tax benefits related to impairment				29
Net discrete tax (benefits) charges related to tax settlements		$ 19		120	$ (25)	$ 1
Net tax benefits from excess foreign tax credits upon repatriation of prior foreign earnings and accrual on certain foreign earnings					16
Net tax benefits from change in valuation allowance				15	6
Net tax benefits for return to provision adjustments related to tax return filings					(4)
Other miscellaneous tax items				$ 2	1
Foreign currency transaction gain (loss), before tax						(3)
Cost of renewal of the U.S. research and experimentation credit						1
Income tax rate	21.00%		35.00%	24.53%
Percentage of dividend received deduction for foreign dividends				100.00%
Provisional tax expense		(4)		$ 13
Income tax rate for aggregate cash position			15.50%
Income tax rate for exceeds aggregate cash position			8.00%
(Provision) benefit for income taxes for deemed repatriation		6		$ (138)
Percentage of deduction for dividends from specified foreign corporations				100.00%
Provisional amount to tax expense		(16)		$ 8
Percentage of tax on foreign income in excess of a deemed return on tangible assets of foreign corporations	10.50%
Net operating loss carryforwards		768		768
Other tax credit carryforwards		98		98
Undistributed earnings		917		917
Required future taxable operating income				$ 472
Expected term to realize deferred tax asset, years				20 years
Increased/(decreased) valuation allowance				$ 1	(9)
Unrecognized tax benefits		37		37	36	30	$ 30
Unrecognized tax benefits, recorded		26		26
Unrecognized tax benefits, not recorded		11		11
Accruals for penalties		1		1	1
Accruals for interest		9		9	8
Total penalties and interest				2	$ 2	2
Favorable impact on tax provision				$ 35
Earliest Tax Year [Member] | State Tax Authorities [Member]
Income Taxes [Line Items]
Tax years remain subject to examination				2005
Earliest Tax Year [Member] | Non-U.S. Jurisdictions [Member]
Income Taxes [Line Items]
Tax years remain subject to examination				2002
Earliest Tax Year [Member] | United States Internal Revenue Service (IRS) [Member]
Income Taxes [Line Items]
Tax years remain subject to examination				2014
Latest Tax Year [Member] | State Tax Authorities [Member]
Income Taxes [Line Items]
Tax years remain subject to examination				2016
Latest Tax Year [Member] | Non-U.S. Jurisdictions [Member]
Income Taxes [Line Items]
Tax years remain subject to examination				2016
Latest Tax Year [Member] | United States Internal Revenue Service (IRS) [Member]
Income Taxes [Line Items]
Tax years remain subject to examination				2016
U.S. Defined Benefit Plans [Member]
Income Taxes [Line Items]
Net deferred tax assets		$ 99		$ 99
Deferred Income Tax Charge [Member]
Income Taxes [Line Items]
Charge for valuation allowance on deferred tax assets in foreign jurisdiction						$ 5