Employee Benefit Plans (Tables)

12 Months Ended

Sep. 30, 2017

Compensation And Retirement Disclosure [Abstract]

Change in Benefit Obligations and Change in Plan Assets

The following provides information about projected benefit obligations, plan assets, the funded status and weighted-average assumptions of the defined benefit pension and postretirement benefit plans:

	Years Ended September 30
	2017						2016						2017						2016
	Pension Benefits												Postretirement Benefits
	U.S.			Foreign			U.S.			Foreign			U.S.			Foreign			U.S.			Foreign
	(In millions)
Change in Benefit Obligations:
Benefit obligation at beginning of    year	$	175		$	400		$	170		$	348		$	37		$	20		$	38		$	15
Service cost		1			10			1			8			—			—			—			—
Interest cost		4			6			4			8			1			1			1			1
Plan participants’ contribution		—			2			—			2			—			—			—			—
Foreign currency exchange rate    changes		—			16			—			(9	)		—			—			—			(1	)
(Gain) Loss from changes in actuarial    assumptions and plan experience		(7	)		(42	)		14			62			(2	)		(1	)		1			5
Benefits paid		(7	)		(12	)		(7	)		(14	)		(3	)		—			(3	)		—
Settlements or curtailments		(5	)		(3	)		(6	)		(4	)		—			—			—			—
Other		(1	)		(1	)		(1	)		(1	)		—			—			—			—
Benefit obligation at end of year	$	160		$	376		$	175		$	400		$	33		$	20		$	37		$	20

	Years Ended September 30
	2017						2016						2017						2016
	Pension Benefits												Postretirement Benefits
	U.S.			Foreign			U.S.			Foreign			U.S.			Foreign			U.S.			Foreign
	(In millions)
Change in Plan Assets:
Fair value of plan assets at beginning    of year	$	157		$	305		$	153		$	279		$	—		$	—		$	—		$	—
Actual return on plan assets		12			6			18			43			—			—			—			—
Employer contribution		1			9			—			10			3			—			3			1
Plan participants’ contribution		—			2			—			2			—			—			—			—
Foreign currency exchange rate    changes		—			12			—			(11	)		—			—			—			—
Benefits paid		(7	)		(12	)		(7	)		(14	)		(3	)		—			(3	)		(1	)
Settlements		(6	)		(3	)		(6	)		(3	)		—			—			—			—
Expenses paid from assets		(1	)		(1	)		(1	)		(1	)		—			—			—			—
Fair value of plan assets at end    of year	$	156		$	318		$	157		$	305		$	—		$	—		$	—		$	—
Funded status	$	(4	)	$	(58	)	$	(18	)	$	(95	)	$	(33	)	$	(20	)	$	(37	)	$	(20	)
Recognized liability	$	(4	)	$	(58	)	$	(18	)	$	(95	)	$	(33	)	$	(20	)	$	(37	)	$	(20	)

Assumptions Used to Determine Pension Benefit Obligations and Periodic Benefit Costs, Postretirement Benefit Obligations and Net Costs

Pension Assumptions and Strategy

The following assumptions were used to determine the pension benefit obligations and periodic benefit costs as of and for the years ended September 30:

	2017						2016						2015
	Pension Benefits
	U.S.			Foreign			U.S.			Foreign			U.S.			Foreign
Actuarial assumptions as of the year-end    measurement date:
Discount rate		3.6	%		2.4	%		3.4	%		1.8	%		4.2	%		2.9	%
Rate of increase in compensation	N/A				2.7	%	N/A				2.8	%	N/A				2.8	%
Actuarial assumptions used to determine net    periodic benefit cost during the year:
Discount rate - benefit obligation		3.4	%		1.8	%		4.2	%		2.9	%		4.0	%		3.0	%
Discount rate - service cost	N/A				1.8	%	N/A				2.8	%	N/A				3.0	%
Discount rate - interest cost		2.7	%		1.5	%		3.3	%		2.4	%		4.0	%		3.0	%
Expected long-term rate of return on    plan assets		6.8	%		4.7	%		7.5	%		5.1	%		7.5	%		5.4	%
Rate of increase in compensation	N/A				2.8	%	N/A				2.8	%	N/A				2.8	%

Postretirement Assumptions and Strategy

The following assumptions were used to determine the postretirement benefit obligations and net costs as of and for the years ended September 30:

	2017						2016						2015
	Postretirement Benefits
	U.S.			Foreign			U.S.			Foreign			U.S.			Foreign
Actuarial assumptions as of the year-end    measurement date:
Discount rate		3.4	%		3.1	%		3.0	%		2.8	%		3.7	%		3.9	%
Initial health care cost trend rate		7.0	%		7.1	%		7.0	%		6.1	%		6.5	%		6.8	%
Actuarial assumptions used to determine    net cost during the year:
Discount rate - benefit obligation		3.0	%		2.8	%		3.7	%		3.9	%		3.8	%		3.9	%
Discount rate - service cost		2.6	%		3.2	%		3.4	%		4.1	%		3.8	%		3.9	%
Discount rate - interest cost		2.4	%		2.6	%		2.8	%		3.7	%		3.8	%		3.9	%
Initial health care cost trend rate		7.0	%		6.1	%		6.5	%		6.8	%		7.0	%		7.1	%

Amounts Recognized in Consolidated Balance Sheets

Amounts recognized in the Consolidated Balance Sheets at September 30, 2017 and 2016 related to the Company's defined benefit pension and postretirement benefit plans were as follows:

	September 30
	2017						2016						2017						2016
	Pension Benefits												Postretirement Benefits
	U.S.			Foreign			U.S.			Foreign			U.S.			Foreign			U.S.			Foreign
	(In millions)
Noncurrent assets	$	1		$	12		$	—		$	8		$	—		$	—		$	—		$	—
Current liabilities	$	(1	)	$	(1	)	$	—		$	(1	)	$	(3	)	$	(1	)	$	(3	)	$	(1	)
Noncurrent liabilities	$	(4	)	$	(69	)	$	(18	)	$	(102	)	$	(30	)	$	(19	)	$	(34	)	$	(19	)

Amounts Recognized in AOCI

Amounts recognized in AOCI at September 30, 2017 and 2016 related to the Company's defined benefit pension and postretirement benefit plans were as follows:

	September 30
	2017					2016					2017					2016
	Pension Benefits										Postretirement Benefits
	U.S.		Foreign			U.S.		Foreign			U.S.			Foreign		U.S.			Foreign
	(In millions)
Net actuarial (gain) loss	$	3	$	52		$	12	$	92		$	(6	)	$	5	$	(4	)	$	6
Net prior service credit		—		(1	)		—		(1	)		(5	)		—		(7	)		—
Balance in accumulated other    comprehensive income (loss), pretax	$	3	$	51		$	12	$	91		$	(11	)	$	5	$	(11	)	$	6

Estimated Future Benefit Payments

Estimated Future Benefit Payments

The Company expects that the following benefit payments will be made to plan participants in the years from 2018 to 2027:

	Pension Benefits				Postretirement Benefits
Years Ended September 30	U.S.		Foreign		U.S.		Foreign
	(In millions)
2018	$	13	$	13	$	3	$	1
2019	$	12	$	14	$	3	$	1
2020	$	10	$	13	$	3	$	1
2021	$	10	$	17	$	3	$	1
2022	$	10	$	16	$	3	$	1
2023 - 2027	$	50	$	86	$	12	$	5

Net Periodic Defined Benefit Pension and Other Postretirement Benefit Costs

Net periodic defined benefit pension and other postretirement benefit costs include the following components:

	Years Ended September 30
	2017						2016						2015						2017					2016					2015
	Pension Benefits																		Postretirement Benefits
	U.S.			Foreign			U.S.			Foreign			U.S.			Foreign			U.S.			Foreign		U.S.			Foreign		U.S.			Foreign
	(In millions)
Service cost	$	1		$	10		$	1		$	8		$	1		$	9		$	—		$	—	$	—		$	—	$	—		$	—
Interest cost		4			6			4			8			7			11			1			1		1			1		2			1
Expected return on plan    assets		(9	)		(14	)		(10	)		(14	)		(11	)		(14	)		—			—		—			—		—			—
Amortization of prior    service cost		—			—			—			—			—			3			(3	)		—		(3	)		—		(4	)		—
Net losses		—			5			—			3			—			4			—			—		—			—		—			—
Settlements or    Curtailments cost		—			—			—			1			—			18			—			—		(1	)		—		—			—
Net periodic (benefit) cost	$	(4	)	$	7		$	(5	)	$	6		$	(3	)	$	31		$	(2	)	$	1	$	(3	)	$	1	$	(2	)	$	1

Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss), Pre-Tax

Other changes in plan assets and benefit obligations recognized in Other comprehensive income (loss) are as follows:

	Years Ended September 30
	2017						2016					2015					2017						2016				2015
	Pension Benefits																Postretirement Benefits
	U.S.			Foreign			U.S.		Foreign			U.S.		Foreign			U.S.			Foreign			U.S.		Foreign		U.S.			Foreign
	(In millions)
Net (gains) losses	$	(9	)	$	(35	)	$	7	$	31		$	14	$	(8	)	$	(3	)	$	(1	)	$	2	$	5	$	1		$	—
Prior service (credit) cost		—			—			—		—			—		(2	)		—			—			—		—		(11	)		—
Amortization of prior    service credit		—			—			—		—			—		—			3			—			3		—		—			—
Amortization of prior    unrecognized loss		—			(5	)		—		(3	)		—		(4	)		—			—			—		—		4			—
Other		—			—			—		(1	)		—		(27	)		—			—			1		—		—			—
Net changes recognized in    Total other comprehensive    (income) loss (1)	$	(9	)	$	(40	)	$	7	$	27		$	14	$	(41	)	$	—		$	(1	)	$	6	$	5	$	(6	)	$	—

⁽¹⁾ The tax impact on pension and other postretirement benefit liability adjustments arising during the period was a tax provision of $7 million, tax benefit of $7 million, and tax provision of $5 million for fiscal years 2017, 2016, and 2015, respectively.

Sensitivity Analysis

A one percentage point change in the 2017 assumed health care cost trend rate would have an immaterial impact to the aggregate of the service and interest cost components of the net periodic postretirement benefit and would have the following effect on the postretirement benefit obligation:

	1-Percentage-Point
	Increase				Decrease
	U.S.		Foreign		U.S.		Foreign
	(In millions)
Effect on postretirement benefit obligation	$	—	$	3	$	—	$	(3	)

Defined Benefit Pension Plans Weighted-Average Asset Allocations

The Company’s defined benefit pension plans weighted-average asset allocations at September 30, 2017 and 2016, by asset category, are as follows:

	September 30
	2017						2016
	Pension Assets
	U.S.			Foreign			U.S.			Foreign
Equity securities		48	%		39	%		50	%		39	%
Debt securities		5	%		53	%		50	%		53	%
Cash and other securities(1)		47	%		8	%		—	%		8	%
Total		100	%		100	%		100	%		100	%

⁽¹⁾ Prior to year-end, within the U.S. defined benefit pension plan, the Company transitioned the majority of its fixed income assets held in a mutual fund investment to a separately managed account.  This transition process temporarily resulted in a larger percentage of the assets being held in cash or cash equivalents on September 30, 2017.

Fair Value of Pension Plan Assets by Asset Category

The fair value of the Company’s pension plan assets at September 30, 2017 and 2016 by asset category is as follows:

	September 30
	2017						2016
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Observable Inputs (Level 2)		Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Observable Inputs (Level 2)		Total
	(In millions)
Cash	$	1	$	—	$	1	$	1	$	—	$	1
Direct investments:
U.S. equity securities		—		—		—		18		—		18
Total direct investments		—		—		—		18		—		18
Investment funds:
Equity funds(1)		75		124		199		59		119		178
Fixed income funds(2)		8		168		176		79		162		241
Real estate funds(3)		—		9		9		1		8		9
Cash equivalent funds		74		—		74		—		1		1
Total investment funds		157		301		458		139		290		429
Alternative investments:
Insurance contracts(4)		—		15		15		—		14		14
Total alternative investments		—		15		15		—		14		14
Total pension plan assets	$	158	$	316	$	474	$	158	$	304	$	462

⁽¹⁾ The equity funds asset class includes funds that invest in U.S. equities as well as equity securities issued by companies incorporated, listed or domiciled in countries in developed and/or emerging markets. These companies may be in the small-, mid- or large-cap categories.

⁽²⁾ The fixed income funds asset class includes investments in high quality funds. High quality fixed income funds primarily invest in low risk U.S. and non-U.S. government securities, investment-grade corporate bonds, mortgages and asset-backed securities. A significant portion of the fixed income funds include investment in long-term bond funds.

⁽³⁾ The real estate funds asset class includes funds that primarily invest in entities which are principally engaged in the ownership, acquisition, development, financing, sale and/or management of income-producing real estate properties, both commercial and residential. These funds typically seek long-term growth of capital and current income that is above average relative to public equity funds.

⁽⁴⁾ Insurance contracts held by the Company’s non-U.S. plans are issued by well-known, highly rated insurance companies.