Discontinued Operations Discontinued Operations - Assets and Liabilities Held for Sale, Specific Transactions (Details) - USD ($) $ in Millions	Mar. 31, 2017	Sep. 30, 2016
Assets and Liabilities Held for Sale, Specific Transactions [Line Items]
Assets held for sale	$ 2,037	$ 5,812
Liabilities held for sale	237	4,276
Building Technologies & Solutions Tyco [Member] | Scott Safety business [Member]
Assets and Liabilities Held for Sale, Specific Transactions [Line Items]
Accounts receivable - net	93	9
Inventories	66	7
Other current assets	10	3
Property, plant and equipment - net	74	15
Goodwill	1,261	89
Other intangible assets - net	533	30
Other noncurrent assets	0	4
Assets held for sale	2,037	157
Accounts payable	33	9
Accrued compensation and benefits	9	0
Other current liabilities	22	19
Other noncurrent liabilities	173	0
Liabilities held for sale	$ 237	28
Corporate Segment
Assets and Liabilities Held for Sale, Specific Transactions [Line Items]
Assets held for sale		$ 17