Document and Entity Information Document - USD ($)	12 Months Ended
	Dec. 31, 2015	Feb. 05, 2016	Jun. 30, 2015
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, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--12-31
Amendment Flag	false
Entity Filer Category	Large Accelerated Filer
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 10,443,430,912
Class A common stock, voting
Document Information [Line Items]
Entity Common Stock, shares outstanding		2,562,594
Class B common stock, non-voting
Document Information [Line Items]
Entity Common Stock, shares outstanding		193,203,589
Class A exchangeable shares
Document Information [Line Items]
Entity Common Stock, shares outstanding		2,888,691
Class B Exchangeable Shares [Member]
Document Information [Line Items]
Entity Common Stock, shares outstanding		15,781,149