Document and Entity Information Document (USD $) In Thousands, except Share data	6 Months Ended
	May 29, 2011	Jun. 04, 2011
Entity Information [Line Items]
Entity Registrant Name	AMERON INTERNATIONAL CORPORATION
Entity Central Index Key	0000790730
Current Fiscal Year End Date	--11-30
Document Fiscal Year Focus	2011
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	May 29, 2011
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding		9,069,126
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float		$ 8,797,456