RETIREMENT MEDICAL PLANS (Details 4) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Amount Of Retiree Medical Obligations Recorded In Accumulated Other Comprehensive Loss Net Of Tax [Abstract]
Deferred tax impact	$ (2)	$ (12)	$ (2)
Retiree Medical Plan [Member]
Amount Of Retiree Medical Obligations Recorded In Accumulated Other Comprehensive Loss Net Of Tax [Abstract]
Balance, beginning	150	191
Net actuarial gain for the year	(3)	(20)
Curtailment gain	(16)	(5)
Recognized prior service costs due to curtailment	15
Amortization for the year	(16)	(19)
Deferred tax impact	(1)	3
Balance, ending	129	150
Retiree Medical Plan [Member] | Net Actuarial Loss [Member]
Amount Of Retiree Medical Obligations Recorded In Accumulated Other Comprehensive Loss Net Of Tax [Abstract]
Balance, beginning	169	197
Net actuarial gain for the year	(3)	1
Curtailment gain	0	(5)
Recognized prior service costs due to curtailment	0
Amortization for the year	(23)	(27)
Deferred tax impact	(1)	3
Balance, ending	142	169
Retiree Medical Plan [Member] | Prior Service Cost (Benefit) [Member]
Amount Of Retiree Medical Obligations Recorded In Accumulated Other Comprehensive Loss Net Of Tax [Abstract]
Balance, beginning	(19)	(6)
Net actuarial gain for the year	0	(21)
Curtailment gain	(16)	0
Recognized prior service costs due to curtailment	15
Amortization for the year	7	8
Deferred tax impact	0	0
Balance, ending	$ (13)	$ (19)