Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2012	Mar. 20, 2013	Jun. 30, 2012
Document and Entity Information [Abstract]
Entity Registrant Name	AMERICAN LOCKER GROUP INC
Entity Central Index Key	0000008855
Document Type	10-K/A
Document Period End Date	Dec. 31, 2012
Amendment Flag	true
Amendment Description	This Amendment No. 1 to the Annual Report on Form 10-K for the fiscal year ended December 31, 2012 of American Locker Group Incorporated is filed for the purpose of correcting a typographical error in the Consolidated Balance Sheet as of December 31, 2011.
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Smaller Reporting Company
Entity Public Float			$ 1,506,251
Entity Common Stock, Shares Outstanding		1,687,319