Discontinued Operations Discontinued Operations - Results of Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Financial Results of Discontinued Operations [Abstract]
Net sales		$ 1,037	$ 5,746
Cost of sales		701	3,741
SG&A		263	1,370
Other (income) deductions, net		(473)	321
Earnings (Loss) before income taxes		546	314
Income taxes	$ 0	671	269
Earnings (Loss), net of tax	$ 0	(125)	45
Network Power Systems Business | Discontinued Operations, Disposed of by Sale [Member]
Financial Results of Discontinued Operations [Abstract]
Net sales		630
Cost of sales		394
SG&A		180
Other (income) deductions, net		(515)
Earnings (Loss) before income taxes		571
Income taxes		577
Earnings (Loss), net of tax		(6)
Network Power Systems Business | Discontinued Operations, Held-for-sale [Member]
Financial Results of Discontinued Operations [Abstract]
Net sales			4,378
Cost of sales			2,708
SG&A			1,101
Other (income) deductions, net			172
Earnings (Loss) before income taxes			397
Income taxes			218
Earnings (Loss), net of tax			179
Power Generation, Motors and Drives Business | Discontinued Operations, Disposed of by Sale [Member]
Financial Results of Discontinued Operations [Abstract]
Net sales		407
Cost of sales		307
SG&A		83
Other (income) deductions, net		42
Earnings (Loss) before income taxes		(25)
Income taxes		94
Earnings (Loss), net of tax		$ (119)
Power Generation, Motors and Drives Business | Discontinued Operations, Held-for-sale [Member]
Financial Results of Discontinued Operations [Abstract]
Net sales			1,368
Cost of sales			1,033
SG&A			269
Other (income) deductions, net			149
Earnings (Loss) before income taxes			(83)
Income taxes			51
Earnings (Loss), net of tax			$ (134)