Cover - shares	6 Months Ended
	Jul. 03, 2021	Aug. 03, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jul. 03, 2021
Document Transition Report	false
Entity File Number	001-11311
Entity Registrant Name	LEAR CORP
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	13-3386776
Entity Address, Address Line One	21557 Telegraph Road
Entity Address, City or Town	Southfield
Entity Address, State or Province	MI
Entity Address, Postal Zip Code	48033
City Area Code	248
Local Phone Number	447-1500
Title of 12(b) Security	Common stock, par value $0.01
Trading Symbol	LEA
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		59,741,379
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Entity Central Index Key	0000842162
Current Fiscal Year End Date	--12-31