Document And Entity Information (USD $)	12 Months Ended
	Dec. 31, 2011	Jun. 30, 2011	Feb. 24, 2012 Common Class B [Member]	Feb. 24, 2012 Common Class A [Member]
Entity Registrant Name	LITHIA MOTORS INC
Document Type	10-K
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding			3,762,231	22,235,942
Entity Public Float		$ 445,604,000
Amendment Flag	false
Entity Central Index Key	0001023128
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Well-known Seasoned Issuer	No
Document Period End Date	Dec. 31, 2011
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	FY