Revenue Recognition - Disaggregation of Revenue by Geographical Market (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Total	$ 4,158	$ 4,204
United States
Disaggregation of Revenue [Line Items]
Total	1,425	1,293
Germany
Disaggregation of Revenue [Line Items]
Total	323	424
Mexico
Disaggregation of Revenue [Line Items]
Total	590	547
Other European countries
Disaggregation of Revenue [Line Items]
Total	1,289	1,422
Other foreign
Disaggregation of Revenue [Line Items]
Total	839	828
Operating segments
Disaggregation of Revenue [Line Items]
Total	4,466	4,514
Elimination
Disaggregation of Revenue [Line Items]
Total	(308)	(310)
Seating
Disaggregation of Revenue [Line Items]
Total	3,738	3,795
Seating | Operating segments
Disaggregation of Revenue [Line Items]
Total	3,739	3,796
Seating | Operating segments | United States
Disaggregation of Revenue [Line Items]
Total	1,183	1,067
Seating | Operating segments | Germany
Disaggregation of Revenue [Line Items]
Total	212	285
Seating | Operating segments | Mexico
Disaggregation of Revenue [Line Items]
Total	480	441
Seating | Operating segments | Other European countries
Disaggregation of Revenue [Line Items]
Total	1,025	1,175
Seating | Operating segments | Other foreign
Disaggregation of Revenue [Line Items]
Total	839	828
Seating | Elimination
Disaggregation of Revenue [Line Items]
Total	(1)	(1)
SS&M
Disaggregation of Revenue [Line Items]
Total	420	409
SS&M | Operating segments
Disaggregation of Revenue [Line Items]
Total	727	718
SS&M | Operating segments | United States
Disaggregation of Revenue [Line Items]
Total	242	226
SS&M | Operating segments | Germany
Disaggregation of Revenue [Line Items]
Total	111	139
SS&M | Operating segments | Mexico
Disaggregation of Revenue [Line Items]
Total	110	106
SS&M | Operating segments | Other European countries
Disaggregation of Revenue [Line Items]
Total	264	247
SS&M | Operating segments | Other foreign
Disaggregation of Revenue [Line Items]
Total	0	0
SS&M | Elimination
Disaggregation of Revenue [Line Items]
Total	$ (307)	$ (309)