Note 16. Income Taxes statement details (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended	12 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Valuation Allowance					$ 1,407
Undistributed Earnings of Domestic Subsidiaries					1,100
Restructuring Costs and Asset Impairment Charges					$ 46	$ 332	$ 182
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent					0.00%
Unrecognized Tax Benefits	$ 596				$ 193	596	390	$ 284
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Deferred Rent	431				83	431
Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount						136	336
Income Tax Expense (Benefit)					99	1,839	418
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount						0	15
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount					(67)	(92)	(13)
Effective Income Tax Rate Reconciliation, Tax Contingency, Foreign, Amount						(207)	(252)
Effective Income Tax Rate Reconciliation, Deduction, Amount					21
Effective Income Tax Rate Reconciliation, Tax Credit, Amount						7	6
Effective Income Tax Rate Reconciliation, Disposition of Business, Amount						1,988	356
Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Amount							75
Unrecognized Tax Benefits, Period Increase (Decrease)						471
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount						14	(13)
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount						7	(5)
Deferred Tax Assets, Net	832				746	832
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits	95				58	95
Deferred Tax Assets, Operating Loss Carryforwards	288				340	288
Deferred Tax Assets, Property, Plant and Equipment	0				3	0
Deferred Tax Assets, Goodwill and Intangible Assets	0				463	0
Deferred Tax Assets, in Process Research and Development	9				9	9
Deferred Tax Assets, Investment in Subsidiaries	265				0	265
Deferred Tax Assets, Other	11				13	11
Deferred Tax Assets, Gross	1,099				969	1,099
Deferred Tax Assets, Valuation Allowance	267				223	267
Deferred Tax Liabilities, Property, Plant and Equipment	23				0	23
Deferred Tax Liabilities, Undistributed Foreign Earnings	108				95	108
Deferred Tax Liabilities, Intangible Assets	110				0	110
Deferred Tax Liabilities, Investment in Noncontrolled Affiliates	0				15	0
Deferred Tax Liabilities, Gross	241				110	241
Deferred Tax Liabilities, Net	591				636	591
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions					76	288	138
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions					5	0	0
Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions					471	65	32
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities					7	15	0
Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations					6	2	0
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	11				3	11	10
Other Tax Expense (Benefit)					5		218
Undistributed Earnings of Foreign Subsidiaries					14,100
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Restructuring Charges, Amount			$ 7
Tax Adjustments, Settlements, and Unusual Provisions	89	$ 85	$ 778	$ 1,891
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain					151	0	0
Income Taxes Paid					148
PaidPriortoSeparation					$ 16
Hungarian Tax Rate Change					0.00%
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration					$ 809
Deferred Tax Assets, Operating Loss Carryforwards, Not Subject to Expiration					468
SOUTH AFRICA
Operating Loss Carryforwards [Line Items]
Valuation Allowances and Reserves, Period Increase (Decrease)							13
UNITED KINGDOM
Operating Loss Carryforwards [Line Items]
Valuation Allowances and Reserves, Period Increase (Decrease)						12
SLOVAKIA
Operating Loss Carryforwards [Line Items]
Valuation Allowances and Reserves, Period Increase (Decrease)						5
GERMANY
Operating Loss Carryforwards [Line Items]
Valuation Allowances and Reserves, Period Increase (Decrease)						83
IRELAND
Operating Loss Carryforwards [Line Items]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest					(6)	0	0
UNITED STATES
Operating Loss Carryforwards [Line Items]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest					122	330	493
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest					945	47	451
IRELAND
Operating Loss Carryforwards [Line Items]
Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount					133
Income Tax Expense (Benefit)					99
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount					(10)
Effective Income Tax Rate Reconciliation, Deduction, Amount					28
Effective Income Tax Rate Reconciliation, Tax Credit, Amount					13
Effective Income Tax Rate Reconciliation, Equity in Earnings (Losses) of Unconsolidated Subsidiary, Amount					(19)
Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Amount					30
Effective Income Tax Rate Reconciliation, Tax Credit, Foreign, Amount					11
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount					10
Unrecognized Tax Benefits, Period Increase (Decrease)					50
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount					21
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount					3
Other Noncurrent Assets [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Net, Noncurrent	613				1,025	613
Other Noncurrent Liabilities [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Liabilities, Net, Noncurrent	22				389	22
Deferred Tax Asset [Domain]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Net	$ 591				$ 636	$ 591
Secretariat of the Federal Revenue Bureau of Brazil [Member] | Tax Year 2012 [Member]
Operating Loss Carryforwards [Line Items]
Income Tax Examination, Year under Examination					2012
State Administration of Taxation, China [Member] | Tax Year 2011 [Member]
Operating Loss Carryforwards [Line Items]
Income Tax Examination, Year under Examination					2011
MTS CZECH REPUBLIC [Member] | Tax Year 2008 [Member]
Operating Loss Carryforwards [Line Items]
Income Tax Examination, Year under Examination					2008
Ministry of the Economy, Finance and Industry, France [Member] | Tax Year 2013 [Member]
Operating Loss Carryforwards [Line Items]
Income Tax Examination, Year under Examination					2013
Federal Ministry of Finance, Germany [Member] | Tax Year 2013 [Member]
Operating Loss Carryforwards [Line Items]
Income Tax Examination, Year under Examination					2013
Inland Revenue, Hong Kong [Member] | Tax Year 2011 [Member]
Operating Loss Carryforwards [Line Items]
Income Tax Examination, Year under Examination					2011
National Tax Agency, Japan [Member] | Tax Year 2012 [Member]
Operating Loss Carryforwards [Line Items]
Income Tax Examination, Year under Examination					2012
Luxembourg Inland Revenue [Member] | Tax Year 2008 [Member]
Operating Loss Carryforwards [Line Items]
Income Tax Examination, Year under Examination					2012
Mexican Tax Authority [Member] | Tax Year 2012 [Member]
Operating Loss Carryforwards [Line Items]
Income Tax Examination, Year under Examination					2012
KDPW_CCP [Member] | Tax Year 2008 [Member]
Operating Loss Carryforwards [Line Items]
Income Tax Examination, Year under Examination					2008
HSBC-X UNITED KINGDOM [Member] | Tax Year 2011 [Member]
Operating Loss Carryforwards [Line Items]
Income Tax Examination, Year under Examination					2011
State and Local Jurisdiction [Member] | Latest Tax Year [Member]
Operating Loss Carryforwards [Line Items]
Income Tax Examination, Year under Examination					2017
GAAS [Member]
Operating Loss Carryforwards [Line Items]
Noncash or Part Noncash Acquisition, Intangible Assets Acquired					$ 276
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life					20 years
Unrecognized Tax Benefits, Increase Resulting from Acquisition					$ 69
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain					151
Futuris [Member]
Operating Loss Carryforwards [Line Items]
Business Combination, Separately Recognized Transactions, Additional Disclosures, Acquisition Cost Expensed					3
Noncash or Part Noncash Acquisition, Intangible Assets Acquired					$ 165
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life					10 years
Unrecognized Tax Benefits, Increase Resulting from Acquisition					$ 64
Interiors Segment [Member]
Operating Loss Carryforwards [Line Items]
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain							127
Extraordinary Item, Gain (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest							$ 20