Discontinued Operations Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued operations, net of tax	$ 0	$ (84)	$ 0	$ (139)
Network Power Systems Business [Member] | Discontinued Operations, Disposed of by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Agreed-upon purchase price of business				4,000
Gain (loss) on sale of business, net of tax				100
Gain on sale of business, pretax				465
Power Generation, Motors and Drives Business [Member] | Discontinued Operations, Disposed of by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Agreed-upon purchase price of business				1,200
Gain (loss) on sale of business, net of tax				(172)
Loss on sale of business, pretax				38
Combined, Network Power and Power Generation, motors and Drives Business [Member] | Discontinued Operations, Disposed of by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net earnings (loss) from operations of discontinued operations, net of tax				6
Income tax expense for repatriation of cash				103
Benefit from ceasing depreciation on assets from discontinued operations				$ 30