New Accounting Standards Recently Adopted Accounting Pronouncements (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018	Sep. 30, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Income from discontinued operations, net of tax (Note 4)	$ 284		$ 265	$ 547	$ 583
Revenue, Net	5,779		5,630	11,243	10,935
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	321		$ 254	565	$ 424
Accounts receivable - net	5,707			5,707		$ 5,622
Inventories	2,124			2,124		1,819
Assets held for sale	2,999			2,999		3,015
Other current assets	1,767			1,767		1,182
Property, plant and equipment - net	3,332			3,332		3,300
Noncurrent assets held for sale	5,229			5,229		5,188
Other noncurrent assets	1,829			1,829		3,070
Deferred revenue	1,521			1,521		1,326
Liabilities held for sale	1,558			1,558		1,791
Retained earnings	6,416			6,416		$ 6,604
Accounting Standards Update 2016-16 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect on Retained Earnings, Net of Tax				546
Accounting Standards Update 2016-01 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect on Retained Earnings, Net of Tax				0
Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect on Retained Earnings, Net of Tax				45
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable - net	(34)			(34)
Inventories	(14)			(14)
Assets held for sale	16			16
Other current assets	(25)			(25)
Property, plant and equipment - net	40			40
Other noncurrent assets	30			30
Deferred revenue	9			9
Liabilities held for sale	23			23
Retained earnings	(19)			(19)
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue, Net				1
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest				1
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Power Solutions | Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	272			590
Income from discontinued operations, net of tax (Note 4)	16			26
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable - net	5,741			5,741
Inventories	2,138			2,138
Assets held for sale	2,983			2,983
Other current assets	1,792			1,792
Property, plant and equipment - net	3,292			3,292
Other noncurrent assets	1,799			1,799
Deferred revenue	1,512			1,512
Liabilities held for sale	1,535			1,535
Retained earnings	$ 6,435			6,435
Retained Earnings | Accounting Standards Update 2016-16 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect on Retained Earnings, Net of Tax				546
Retained Earnings | Accounting Standards Update 2016-01 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect on Retained Earnings, Net of Tax		$ (8)		(8)
Retained Earnings | Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect on Retained Earnings, Net of Tax				$ 45