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Segment Reporting - Summary of Segment Financial Information (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 29, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenues from external customers	$ 4,942.4	$ 4,891.6	$ 5,580.8	$ 5,733.7	$ 5,363.8	$ 4,981.5	$ 5,123.2	$ 4,998.5	$ 21,148.5	$ 20,467.0	$ 18,557.6
Segment earnings									1,654.1	1,608.3	1,461.4
Depreciation and amortization									484.4	427.7	378.2
Capital expenditures									677.0	594.5	528.3
Total assets	11,600.7				11,945.9				11,600.7	11,945.9
Operating segments
Segment Reporting Information [Line Items]
Segment earnings									1,892.1	1,892.4	1,727.3
Operating segments \| Seating
Segment Reporting Information [Line Items]
Revenues from external customers									16,021.9	15,873.0	14,356.7
Segment earnings									1,263.6	1,250.8	1,136.0
Depreciation and amortization									323.5	289.5	258.1
Capital expenditures									459.8	398.3	341.6
Total assets	6,857.5				7,303.4				6,857.5	7,303.4
Operating segments \| E-Systems
Segment Reporting Information [Line Items]
Revenues from external customers									5,126.6	4,594.0	4,200.9
Segment earnings									628.5	641.6	591.3
Depreciation and amortization									146.2	123.4	107.6
Capital expenditures									208.4	176.3	162.4
Total assets	2,452.0				2,268.0				2,452.0	2,268.0
Other
Segment Reporting Information [Line Items]
Revenues from external customers									0.0	0.0	0.0
Segment earnings									(238.0)	(284.1)	(265.9)
Depreciation and amortization									14.7	14.8	12.5
Capital expenditures									8.8	19.9	$ 24.3
Total assets	$ 2,291.2				$ 2,374.5				$ 2,291.2	$ 2,374.5