Discontinued Operations Disposal Group - Assets Held For Sale (Details) - USD ($) $ in Millions	Jun. 30, 2017	Sep. 30, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale	$ 2,082	$ 5,812
Liabilities held for sale	247	4,276
Corporate Segment | Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale		17
Building Technologies & Solutions Tyco [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Accounts receivable - net	101	9
Inventories	73	7
Other current assets	8	3
Property, plant and equipment - net	76	15
Goodwill	1,270	89
Other intangible assets - net	554	30
Other noncurrent assets	0	4
Assets held for sale	2,082	157
Accounts payable	34	9
Accrued compensation and benefits	10	0
Other current liabilities	22	19
Other noncurrent liabilities	181	0
Liabilities held for sale	$ 247	$ 28