Segment Reporting - Summary of Revenues from External Customers and Other Financial Information by Reportable Operating Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 03, 2021		Apr. 04, 2020	Dec. 31, 2020
Segment Reporting Information [Line Items]
Revenues from external customers	$ 5,354.4		$ 4,457.7
Segment earnings	307.4		173.4
Depreciation and amortization	140.8		130.5
Capital expenditures	112.9		109.1
Total assets	13,422.5	[1]	13,022.3	$ 13,198.6
Other
Segment Reporting Information [Line Items]
Revenues from external customers	0.0		0.0
Segment earnings	(73.9)		(45.1)
Depreciation and amortization	3.8		3.9
Capital expenditures	6.7		1.2
Total assets	2,167.7		3,240.2
Seating
Segment Reporting Information [Line Items]
Revenues from external customers	3,996.0		3,366.6
Seating | Operating segments
Segment Reporting Information [Line Items]
Revenues from external customers	3,996.0		3,366.6
Segment earnings	292.0		186.1
Depreciation and amortization	90.4		83.5
Capital expenditures	63.0		66.2
Total assets	7,761.2		6,861.8
E-Systems
Segment Reporting Information [Line Items]
Revenues from external customers	1,358.4		1,091.1
E-Systems | Operating segments
Segment Reporting Information [Line Items]
Revenues from external customers	1,358.4		1,091.1
Segment earnings	89.3		32.4
Depreciation and amortization	46.6		43.1
Capital expenditures	43.2		41.7
Total assets	$ 3,493.6		$ 2,920.3

[1] Unaudited.