Postretirement Benefits - Effect of Significant Inputs (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2012
Health and Life Insurance Benefits
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year			$ 437
Fair value of plan assets at end of year	415	447	437
Health and Life Insurance Benefits | Hedge Funds [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	22	21
Health and Life Insurance Benefits | Hedge Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	21	19
Defined Benefit Plan, Actual Return on Plan Assets Still Held	1	2
Defined Benefit Plans, Realized Gains	0	0
Defined Benefit Plan, Purchases, Sales, and Settlements	0	0
Fair value of plan assets at end of year	22	21
Health and Life Insurance Benefits | Private Equity Funds [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	23	26
Health and Life Insurance Benefits | Private Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	26	23
Defined Benefit Plan, Actual Return on Plan Assets Still Held	3	5
Defined Benefit Plans, Realized Gains	4	0
Defined Benefit Plan, Purchases, Sales, and Settlements	(10)	(2)
Fair value of plan assets at end of year	23	26
Pension Benefits
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year			2,411
Fair value of plan assets at end of year	2,627	2,519	2,411
Pension Benefits | Hedge Funds [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	106	101
Pension Benefits | Hedge Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	101	92
Defined Benefit Plan, Actual Return on Plan Assets Still Held	5	8
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	0	1
Defined Benefit Plan, Purchases, Sales, and Settlements	0	0
Fair value of plan assets at end of year	106	101
Pension Benefits | Private Equity Funds [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	94	103
Pension Benefits | Private Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	103	92
Defined Benefit Plan, Actual Return on Plan Assets Still Held	10	18
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	15	0
Defined Benefit Plan, Purchases, Sales, and Settlements	(34)	(7)
Fair value of plan assets at end of year	94	103
Pension Benefits | Real Estate [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	1	1
Pension Benefits | Real Estate [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	1	1
Defined Benefit Plan, Actual Return on Plan Assets Still Held	0	0
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	0	0
Defined Benefit Plan, Purchases, Sales, and Settlements	0	0
Fair value of plan assets at end of year	1	1
Pension Benefits | Fixed Income Interest Rate [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	1	(13)
Pension Benefits | Fixed Income Interest Rate [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	(13)	19
Defined Benefit Plan, Actual Return on Plan Assets Still Held	14	(32)
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	0	4
Defined Benefit Plan, Purchases, Sales, and Settlements	0	(4)
Fair value of plan assets at end of year	1	(13)
Pension Benefits | Equity [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	(106)	(72)
Pension Benefits | Equity [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	(72)	4
Defined Benefit Plan, Actual Return on Plan Assets Still Held	(43)	(90)
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	0	10
Defined Benefit Plan, Purchases, Sales, and Settlements	9	4
Fair value of plan assets at end of year	$ (106)	$ (72)