Document and Entity Information Document (USD $)	12 Months Ended
	Dec. 31, 2013	Jun. 28, 2013	Feb. 07, 2014 Class A common stock, voting	Feb. 07, 2014 Class B common stock, non-voting	Feb. 07, 2014 Class A exchangeable shares	Feb. 07, 2014 Class B exchangeable shares
Document Information [Line Items]
Entity Registrant Name	MOLSON COORS BREWING CO
Trading Symbol	tap
Entity Central Index Key	0000024545
Document Type	10-K
Document Period End Date	Dec. 31, 2013
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--12-31
Amendment Flag	false
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, shares outstanding			2,556,894	159,737,216
Entity Exchangeable, shares outstanding					2,896,941	18,935,453
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float		$ 7,089,069,915