Document and Entity Information	3 Months Ended				3 Months Ended
	Mar. 31, 2013	May 01, 2013 Common Class A [Member]	May 01, 2013 Common Class B [Member]	May 01, 2013 Class Units [Member]	Mar. 31, 2013 LAMAR MEDIA CORP [Member]
Entity Information [Line Items]
Document Type	10-Q				10-Q
Amendment Flag	false				false
Document Period End Date	Mar. 31, 2013				Mar. 31, 2013
Document Fiscal Year Focus	2013				2013
Document Fiscal Period Focus	Q1				Q1
Trading Symbol	LAMR
Entity Registrant Name	LAMAR ADVERTISING CO/NEW				LAMAR MEDIA CORP/DE
Entity Central Index Key	0001090425				0000899045
Current Fiscal Year End Date	--12-31				--12-31
Entity Filer Category	Large Accelerated Filer				Non-accelerated Filer
Entity Common Stock, Shares Outstanding		79,672,676	14,610,365	100