Contingencies - Additional Information (Details) $ in Millions		3 Months Ended		6 Months Ended
	Dec. 12, 2015 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($) claim	Mar. 31, 2017 USD ($) site claim	Sep. 30, 2009 USD ($)
Loss Contingencies [Line Items]
Environmental accrual balance			$ 13	$ 12
Discounted amount environmental accrual for on-going operations maintenance and monitoring				7
Undiscounted amount environmental accrual for on-going operations maintenance and monitoring				7
Maremont Asbestos
Loss Contingencies [Line Items]
Environmental accrual balance			$ 72	$ 73
Number of pending claims | claim			5,800	5,800
Obligation period for asbestos personal injury claims				10 years
Pending and future claims			$ 70	$ 70
Estimated insurance recoveries			32	29
Maremont Asbestos | Insurance Settlement
Loss Contingencies [Line Items]
Cash settlement	$ 17
Litigation settlement, expense	5	$ 3	9
Increased liability	$ 12
Rockwell Asbestos
Loss Contingencies [Line Items]
Environmental accrual balance			$ 61	$ 66
Number of pending claims | claim			3,200	2,600
Obligation period for asbestos personal injury claims				10 years
Pending and future claims			$ 60	$ 60
Estimated insurance recoveries			27	27
Rockwell Asbestos | Insurance Settlement
Loss Contingencies [Line Items]
Cash settlement			32
Litigation settlement, expense			10	8
Increased liability			22
Receivable recorded			12
Rockwell Asbestos | Insurance Settlement 2
Loss Contingencies [Line Items]
Receivable recorded			6
Sisamex
Loss Contingencies [Line Items]
Increased liability				$ 10
Low Range
Loss Contingencies [Line Items]
Site contingency, accrual, discount rate				1.00%
Low Range | Maremont Asbestos
Loss Contingencies [Line Items]
Possible loss			70
Low Range | Rockwell Asbestos
Loss Contingencies [Line Items]
Possible loss			60
High Range
Loss Contingencies [Line Items]
Site contingency, accrual, discount rate				3.00%
High Range | Maremont Asbestos
Loss Contingencies [Line Items]
Possible loss			83
High Range | Rockwell Asbestos
Loss Contingencies [Line Items]
Possible loss			75
Superfund Sites
Loss Contingencies [Line Items]
Number of Superfund environmental sites | site				9
Environmental costs reasonably possible				$ 8
Environmental accrual balance			2	2
Non-Superfund Sites
Loss Contingencies [Line Items]
Environmental costs reasonably possible				31
Environmental accrual balance			11	10
Insurance Receivables | Rockwell Asbestos
Loss Contingencies [Line Items]
Estimated insurance recoveries			9	9
Indemnity Obligations
Loss Contingencies [Line Items]
Guarantee obligations recorded			11	11	$ 28
MSSC
Loss Contingencies [Line Items]
Indemnity obligations liability			1	1
Value Added Tax | Future tax years
Loss Contingencies [Line Items]
Increased liability			$ 10	$ 10