(Tables)

12 Months Ended

Oct. 31, 2017

Oct. 31, 2016

Retirement Benefits [Abstract]

Schedule of Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates [Table Text Block]

The effect of changing the health care cost trend rate by one-percentage point for each future year is as follows:

(in millions)	One-Percentage Point Increase		One-Percentage Point Decrease
Effect on total of service and interest cost components	$	8	$	(6	)
Effect on postretirement benefit obligation	196		(163		)

Components Of Postretirement Benefits Income Expense Included in Statement Of Operations [Table Text Block]

The components of our postretirement benefits expense included in our Consolidated Statements of Operations consist of the following:

	For the Years Ended October 31,
(in millions)	2017			2016		2015
Pension expense	$	121		$	82	$	69
Health and life insurance expense	(3		)	71		81
Total postretirement benefits expense	$	118		$	153	$	150

Schedule of Accumulated Benefit Obligations in Excess of Fair Value of Plan Assets [Table Text Block]

Information for pension plans with accumulated benefit obligations in excess of plan assets were as follows:

	As of October 31,
(in millions)	2017		2016
Projected benefit obligations	$	3,487	$	3,946
Accumulated benefit obligations	3,471		3,934
Fair value of plan assets	2,035		2,224

Schedule of Defined Benefit Plans Disclosures [Table Text Block]

A summary of the changes in benefit obligations and plan assets is as follows:

	Pension Benefits						Health and Life Insurance Benefits
(in millions)	2017			2016			2017			2016
Change in benefit obligations
Benefit obligations at beginning of year	$	4,027		$	3,979		$	1,708		$	1,887
Service cost	7			9			5			5
Interest on obligations	107			118			47			58
Actuarial loss (gain)	(18		)	225			(183		)	(138		)
Settlements	(52		)	—			—			—
Contractual termination benefits	10			3			4			4
Curtailments and other	(2		)	—			(58		)	—
Currency translation	17			(7		)	—			—
Plan participants' contributions	—			—			36			34
Subsidy receipts	—			—			42			37
Benefits paid	(297		)	(300		)	(166		)	(179		)
Benefit obligations at end of year	$	3,799		$	4,027		$	1,435		$	1,708
Change in plan assets
Fair value of plan assets at beginning of year	$	2,310		$	2,422		$	333		$	369
Actual return on plan assets	256			79			38			3
Settlements	(52		)	—			—			—
Currency translation	18			(6		)	—			—
Employer contributions	112			100			2			2
Benefits paid	(281		)	(285		)	(40		)	(41		)
Fair value of plan assets at end of year	$	2,363		$	2,310		$	333		$	333
Funded status at year end	$	(1,436	)	$	(1,717	)	$	(1,102	)	$	(1,375	)

Schedule of Expected Benefit Payments [Table Text Block]

The expected future benefit payments for the years ending October 31, 2018 through 2022 and the five years ending October 31, 2027 are estimated as follows:

(in millions)	Pension Benefit Payments		Other Postretirement Benefit Payments(A)
2018	$	293	$	86
2019	286		82
2020	281		90
2021	273		94
2022	266		96
2023 through 2027	1,219		481

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(A) Payments are net of expected participant contributions and expected federal subsidy receipts.

Schedule of Allocation of Plan Assets [Table Text Block]

Pension Assets

The fair value of the pension plan assets by category is summarized below:

	As of October 31, 2017										As of October 31, 2016
(in millions)	Level 1		Level 2		Level 3		NAV		Total		Level 1		Level 2		Level 3		NAV		Total
Asset Category
Cash and Cash Equivalents	$	86	$	—	$	—	$	—	$	86	$	76	$	—	$	—	$	—	$	76
Equity
U.S. Large Cap	—		—		—		—		—		—		—		—		—		—
U.S. Small-Mid Cap	—		—		—		—		—		—		—		—		—		—
Canadian	—		—		—		—		—		—		—		—		—		—
International	—		—		—		—		—		—		—		—		—		—
Emerging Markets	—		—		—		—		—		—		—		—		—		—
Equity derivative	—		—		—		—		—		—		—		—		—		—
Fixed Income
Corporate and Government Bonds	—		—		—		—		—		—		—		—		—		—
Government Bonds	—		—		—		—		—		—		—		—				—
Asset Backed Securities	—		—		—		—		—		—		—		—		—		—
Collective Trusts and Other
U.S. Equity	316		—		—		—		316		294		—		—		—		294
Canadian Equity	19		—		—		—		19		29		—		—		—		29
International Equity	327		—		—		—		327		291		—		—		—		291
Global Equity	235		—		—		—		235		227		—		—		—		227
Fixed Income - Long Duration Credit	—		508		—		—		508		—		530		—		—		530
Fixed Income - Long Duration Government	—		20		—		—		20		—		—		—		—		—
Fixed Income - High Yield	—		214		—		—		214		—		204		—		—		204
Fixed Income - Canadian Bond	—		213		—		—		213		—		203		—		—		203
Global Real Estate	—		144		—		—		144		—		141		—		—		141
Global Infrastructure	—		—		—		10		10		—		—		—		14		14
Common and Preferred Stock	—		—		—		—		—		—		—		—		—		—
Commodities	—		—		—		—		—		—		—		—		—		—
Hedge Fund of Funds	—		—		—		210		210		—		—		—		230		230
Private Equity	—		—		—		43		43		—		—		—		57		57
Exchange Traded Funds	—		—		—		—		—		—		—		—		—		—
Mutual Funds	—		—		—		—		—		—		—		—		—		—
Real Estate	—		—		1		—		1		—		—		1		—		1
Total(A)	$	983	$	1,099	$	1	$	263	$	2,346	$	917	$	1,078	$	1	$	301	$	2,297

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(A) In addition, the table above includes the fair value of Canadian pension assets translated at the exchange rates as of October 31, 2017 and 2016, respectively, while the change in plan asset table includes the fair value of Canadian pension assets translated at historical foreign currency rates.

The fair value of other postretirement benefit plan assets by category is summarized below:

	As of October 31, 2017										As of October 31, 2016
(in millions)	Level 1		Level 2		Level 3		NAV		Total		Level 1		Level 2		Level 3		NAV		Total
Asset Category
Cash and Cash Equivalents	$	6	$	—	$	—	$	—	$	6	$	19	$	—	$	—	$	—	$	19
Equity
U.S. Large Cap	—		—		—		—		—		—		—		—		—		—
U.S. Small-Mid Cap	—		—		—		—		—		—		—		—		—		—
International	—		—		—		—		—		—		—		—		—		—
Emerging Markets	—		—		—		—		—		—		—		—		—		—
Fixed Income
Corporate and Government Bonds	—		62		—		—		62		—		80		—		—		80
Government Bonds	—		8		—		—		8		—		—		—		—		—
Asset Backed Securities	—		—		—		—		—		—		—		—		—		—
Collective Trusts and Other
U.S. Equity	71		—		—		—		71		66		—		—		—		66
International Equity	74		—		—		—		74		71		—		—		—		71
Fixed Income - Multi-Asset Credit	—		29		—		—		29		—		41		—		—		41
Real Estate (REITs)	—		—		—		24		24		—		—		—		—		—
Mutual Fund	9		—		—		—		9		—		—		—		—		—
Hedge Fund of Funds	—		—		—		39		39		—		—		—		42		42
Private Equity	—		—		—		11		11		—		—		—		14		14
Total	$	160	$	99	$	—	$	74	$	333	$	156	$	121	$	—	$	56	$	333

Schedule of Net Benefit Costs [Table Text Block]

	For the Years Ended October 31,
	Pension Benefits									Health and Life Insurance Benefits
(in millions)	2017			2016			2015			2017			2016			2015
Service cost for benefits earned during the period	$	7		$	9		$	13		$	5		$	5		$	6
Interest on obligation	107			118			142			47			58			71
Amortization of cumulative loss	116			104			97			22			31			39
Amortization of prior service cost (benefit)	—			—			1			—			(1		)	(4		)
Settlements	23			—			—			—			—			—
Contractual termination benefits	10			3			(1		)	4			4			(1		)
Curtailments and other	—			—			—			(58		)	—			—
Premiums on pension insurance	15			15			11			—			—			—
Expected return on assets	(157		)	(167		)	(194		)	(23		)	(26		)	(30		)
Net periodic benefit expense	$	121		$	82		$	69		$	(3	)	$	71		$	81
Other Changes in plan assets and benefit obligations recognized in other comprehensive loss (income)
Actuarial net loss (gain)	$	(116	)	$	313		$	312		$	(197	)	$	(115	)	$	(7	)
Amortization of cumulative loss	(116		)	(104		)	(97		)	(22		)	(31		)	(39		)
Amortization of prior service benefit (cost)	—			—			(1		)	—			1			4
Settlements	(23		)	—			—			—			—			—
Curtailments	(2		)	—			—			—			—			—
Currency translation	—			(1		)	—			—			—			—
Total recognized in other comprehensive loss (income)	$	(257	)	$	208		$	214		$	(219	)	$	(145	)	$	(42	)
Total net postretirement benefits (income) expense and other comprehensive loss (income)	$	(136	)	$	290		$	283		$	(222	)	$	(74	)	$	39

Schedule of Amounts in Accumulated Other Comprehensive Income (Loss) to be Recognized over Next Fiscal Year [Table Text Block]

	Pension Benefits						Health and Life Insurance Benefits
(in millions)	2017			2016			2017			2016
Amounts recognized in our Consolidated Balance Sheets consist of:
Noncurrent asset	$	16		$	6		$	—		$	—
Current liability	(16		)	(17		)	(41		)	(58		)
Noncurrent liability	(1,436		)	(1,706		)	(1,061		)	(1,317		)
Net liability recognized	$	(1,436	)	$	(1,717	)	$	(1,102	)	$	(1,375	)
Amounts recognized in our accumulated other comprehensive loss consist of:
Net actuarial loss	$	2,183		$	2,442		$	252		$	472
Net prior service benefit	—			—			—			—
Net amount recognized	$	2,183		$	2,442		$	252		$	472

The estimated amounts for the defined benefit pension plans and the other postretirement benefit plans that will be amortized from AOCL into net periodic benefit expense over the next fiscal year are as follows:

(in millions)	Pension Benefits		Health and Life Insurance Benefits
Amortization of prior service cost (benefit)	$	—	$	—
Amortization of cumulative losses	106		9

Schedule of Assumptions Used [Table Text Block]

Assumptions

The weighted average rate assumptions used in determining benefit obligations for the years ended October 31, 2017 and 2016 were:

	Pension Benefits				Health and Life Insurance Benefits
	2017		2016		2017		2016
Discount rate used to determine present value of benefit obligation at end of year	3.5	%	3.5	%	3.6	%	3.5	%
Expected rate of increase in future compensation levels	3.5	%	3.5	%	—		—

The weighted average rate assumptions used in determining net postretirement benefits expense for 2017, 2016, and 2015 were:

	Pension Benefits						Health and Life Insurance Benefits
	2017		2016		2015		2017		2016		2015
Discount rate used to determine service cost	3.9	%	4.5	%	3.7	%	4.0	%	4.6	%	3.7	%
Discount rate used to determine interest cost	2.8	%	3.1	%	3.7	%	2.9	%	3.3	%	3.7	%
Expected long-term rate of return on plan assets	7.2	%	7.5	%	7.8	%	7.5	%	7.5	%	7.8	%
Expected rate of increase in future compensation levels	3.5	%	3.5	%	3.5	%	—		—		—