Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2017	Apr. 28, 2017
Document Information [Line Items]
Entity Registrant Name	LITHIA MOTORS INC
Entity Central Index Key	0001023128
Trading Symbol	lad
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	Yes
Document Type	10-Q
Document Period End Date	Mar. 31, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q1
Amendment Flag	false
Common Class B [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding (in shares)		1,262,231
Common Class A [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding (in shares)		23,776,338