Discontinued Operations Disposal Group - Assets Held For Sale (Details) - USD ($) $ in Millions	Mar. 31, 2019	Sep. 30, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale	$ 2,999	$ 3,015
Noncurrent assets held for sale	5,229	5,188
Liabilities held for sale	1,558	1,791
Noncurrent liabilities held for sale	185	207
Power Solutions | Power Solutions | Discontinued Operations, Held-for-sale or Disposed of by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash	45	15
Accounts receivable - net	1,228	1,443
Inventories	1,524	1,405
Other current assets	202	152
Assets held for sale	2,999	3,015
Property, plant and equipment - net	2,981	2,871
Goodwill	1,081	1,092
Other intangible assets - net	156	161
Investments in Partially-Owed Affiliates	476	453
Other noncurrent assets	535	611
Noncurrent assets held for sale	5,229	5,188
Short-term debt	6	9
Current portion of long-term debt	8	25
Accounts payable	1,128	1,237
Accrued compensation and benefits	99	125
Deferred revenue	23	0
Other current liabilities	294	395
Liabilities held for sale	1,558	1,791
Long-term debt	28	31
Pension and postretirement benefits	94	101
Other noncurrent liabilities	63	75
Noncurrent liabilities held for sale	$ 185	$ 207