Investments All Other Equity Investments (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 29, 2012	Dec. 31, 2011		Dec. 25, 2010
Financial Commitments under Distribution Contract [Abstract]
Investment in Equity Method Investment	$ (2,431.8)	$ (2,487.9)
Purchase accounting historical costs corrections		(49.4)	[1]
Historical adjustment, non-cash benefit		(0.2)
Modelo
Financial Commitments under Distribution Contract [Abstract]
Voting control percentage shared by members (as a percent)	50.00%
ABI
Financial Commitments under Distribution Contract [Abstract]
Voting control percentage shared by members (as a percent)	50.00%
Tradeteam Ltd
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	49.90%
Financial Commitments under Distribution Contract [Abstract]
2013	132.6
2014	132.3
2015	112.0
2016	95.5
2017	97.4
Thereafter	73.1
Total	642.9
Financial Commitments on Termination of Distribution Agreement	36.3
Service costs incurred under joint venture	128.5	130.7		117.6
Due to Joint Ventures	14.6	15.6
BRI
Financial Commitments under Distribution Contract [Abstract]
Investment in Equity Method Investment	(41.9)	(28.5)
Purchase accounting historical costs corrections		(55.7)
Historical adjustment, non-cash benefit		4.0
Defined benefit plan adjustments due to change in historical accounting		15.0
Administrative fees related to agreements	124.3	99.5		93.9
Administrative fees receivable related to agreements	37.9	40.9
BDL
Financial Commitments under Distribution Contract [Abstract]
Investment in Equity Method Investment	(8.4)	(12.6)
Administrative fees related to agreements	61.9	41.6		38.5
Administrative fees receivable related to agreements	11.4	13.5
Number of members in distribution operation	2
Voting control percentage shared by members (as a percent)	50.00%
Modelo Molson Imports LP (MMI)
Financial Commitments under Distribution Contract [Abstract]
Voting control percentage shared by members (as a percent)	50.00%
Cost payable to MMI	12.0	15.4		12.3
Administrative fees payable related to agreements	$ 13.1	$ 11.0

[1] As a result of the 2011 correction of an immaterial error in prior periods related to BRI, goodwill decreased $55.7 million. See Note 5, "Investments" under the "Brewers' Retail Inc." sub-heading for further discussion. In addition, as a result of a fixed asset count performed in Canada, goodwill was increased by $6.3 million for the assets identified as not present as of the Merger date. See Note 9, "Special Items," for further discussion.