Segment Reporting - Summary of Revenues from External Customers and Other Financial Information by Reportable Operating Segment (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jul. 03, 2021		Jul. 04, 2020	Jul. 03, 2021		Jul. 04, 2020	Dec. 31, 2020
Segment Reporting Information [Line Items]
Revenues from external customers	$ 4,760.7		$ 2,444.5	$ 10,115.1		$ 6,902.2
Segment earnings	205.5		(294.3)	512.9		(120.9)
Depreciation and amortization	150.2		130.3	291.0		260.8
Capital expenditures	140.0		86.1	252.9		195.2
Total assets	13,263.7	[1]	12,269.0	13,263.7	[1]	12,269.0	$ 13,198.6
Other
Segment Reporting Information [Line Items]
Revenues from external customers	0.0		0.0	0.0		0.0
Segment earnings	(73.3)		(64.5)	(147.2)		(109.6)
Depreciation and amortization	3.8		3.9	7.6		7.8
Capital expenditures	4.7		2.0	11.4		3.2
Total assets	2,268.5		2,680.1	2,268.5		2,680.1
Seating
Segment Reporting Information [Line Items]
Revenues from external customers	3,608.2		1,754.9	7,604.2		5,121.5
Seating | Operating segments
Segment Reporting Information [Line Items]
Revenues from external customers	3,608.2		1,754.9	7,604.2		5,121.5
Segment earnings	252.2		(116.4)	544.2		69.7
Depreciation and amortization	90.1		83.8	180.5		167.3
Capital expenditures	83.5		47.0	146.5		113.2
Total assets	7,528.6		6,687.7	7,528.6		6,687.7
E-Systems
Segment Reporting Information [Line Items]
Revenues from external customers	1,152.5		689.6	2,510.9		1,780.7
E-Systems | Operating segments
Segment Reporting Information [Line Items]
Revenues from external customers	1,152.5		689.6	2,510.9		1,780.7
Segment earnings	26.6		(113.4)	115.9		(81.0)
Depreciation and amortization	56.3		42.6	102.9		85.7
Capital expenditures	51.8		37.1	95.0		78.8
Total assets	$ 3,466.6		$ 2,901.2	$ 3,466.6		$ 2,901.2

[1] Unaudited.