RETIREMENT MEDICAL PLANS (Details 2) (USD $) In Millions, unless otherwise specified	12 Months Ended		3 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2013	Sep. 30, 2014 Retiree Medical Plan [Member]		Sep. 30, 2014 Retiree Medical Plan [Member]		Sep. 30, 2013 Retiree Medical Plan [Member]
APBO - beginning of year	$ 1,794	$ 1,708			$ 511		$ 554
Service cost					0		1
Interest cost					23		21
Participant contributions					2		3
Actuarial gain	27				(2)		(20)
Foreign currency rate changes					(1)		(1)
Curtailment gain			(16)		(16)		(5)
Benefit payments					(40)		(42)
APBO - end of year		1,708	477		477		511
Other			2	[1]	2	[1]	2	[1]
Retiree medical liability			$ 479		$ 479		$ 513

[1] The company recorded a $2 million reserve for retiree medical liabilities at September 30, 2014 and 2013 as its best estimate for retroactive benefits related to the previously mentioned injunction.