Document and Entity Information Document - shares	3 Months Ended
	Mar. 31, 2017	Apr. 28, 2017
Entity Information [Line Items]
Entity Registrant Name	MOLSON COORS BREWING CO
Trading Symbol	tap
Entity Central Index Key	0000024545
Document Type	10-Q
Document Period End Date	Mar. 31, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Amendment Flag	false
Entity Filer Category	Large Accelerated Filer
Common Class A [Member]
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		2,560,948
Common Class B [Member]
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		194,746,610
Class A Exchangeable Shares [Member]
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		2,878,936
Class B Exchangeable Shares [Member]
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		15,093,021