Segment Reporting - Summary of Revenues from External Customers and Other Financial Information by Reportable Operating Segment (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Oct. 02, 2021		Oct. 03, 2020	Oct. 02, 2021		Oct. 03, 2020	Dec. 31, 2020
Segment Reporting Information [Line Items]
Revenues from external customers	$ 4,268.2		$ 4,900.1	$ 14,383.3		$ 11,802.3
Segment earnings	47.6		278.8	560.5		157.9
Depreciation and amortization	140.4		136.3	431.4		397.1
Capital expenditures	152.6		90.1	405.5		285.3
Total assets	13,046.0	[1]	12,894.7	13,046.0	[1]	12,894.7	$ 13,198.6
Other
Segment Reporting Information [Line Items]
Revenues from external customers	0.0		0.0	0.0		0.0
Segment earnings	(71.6)		(57.9)	(218.8)		(167.5)
Depreciation and amortization	3.9		3.7	11.5		11.5
Capital expenditures	8.5		1.1	19.9		4.3
Total assets	2,043.3		2,088.1	2,043.3		2,088.1
Seating
Segment Reporting Information [Line Items]
Revenues from external customers	3,166.2		3,691.6	10,770.4		8,813.1
Seating | Operating segments
Segment Reporting Information [Line Items]
Revenues from external customers	3,166.2		3,691.6	10,770.4		8,813.1
Segment earnings	126.7		250.7	670.9		320.4
Depreciation and amortization	90.3		87.8	270.8		255.1
Capital expenditures	85.2		48.8	231.7		162.0
Total assets	7,405.4		7,574.2	7,405.4		7,574.2
E-Systems
Segment Reporting Information [Line Items]
Revenues from external customers	1,102.0		1,208.5	3,612.9		2,989.2
E-Systems | Operating segments
Segment Reporting Information [Line Items]
Revenues from external customers	1,102.0		1,208.5	3,612.9		2,989.2
Segment earnings	(7.5)		86.0	108.4		5.0
Depreciation and amortization	46.2		44.8	149.1		130.5
Capital expenditures	58.9		40.2	153.9		119.0
Total assets	$ 3,597.3		$ 3,232.4	$ 3,597.3		$ 3,232.4

[1] Unaudited.