Investments MCBC proportional share in MillerCoors (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 29, 2012	Dec. 31, 2011	Dec. 31, 2013 MillerCoors		Dec. 31, 2012 MillerCoors		Dec. 31, 2011 MillerCoors		Dec. 29, 2012 MillerCoors	Dec. 31, 2010 MillerCoors	Dec. 31, 2013 Molson Coors Brewing Company (MCBC)	Dec. 31, 2012 Molson Coors Brewing Company (MCBC)
Schedule of Equity Method Investments [Line Items]
MillerCoors owners' equity	$ 8,638.9	$ 7,966.9		$ 7,470.7		$ 7,266.9
Net income attributable to MillerCoors				1,270.5	[1]	1,190.9	[1]	1,003.8	[1]
MCBC economic Interest (as a percent)				42.00%						42.00%	42.00%	42.00%	42.00%
MCBC proportionate share in MillerCoors' equity												3,137.7	3,052.1
Difference between MCBC contributed cost basis and proportional share of the underlying equity in net assets of MillerCoors												(666.2)	(670.8)
Accounting policy elections												35.0	35.0
Timing differences of cash contributions and distributions as a result of different fiscal periods												0	15.5
Investment in MillerCoors	2,506.5	2,431.8										2,506.5	2,431.8
MCBC proportionate share of MillerCoors net income				533.6		500.2		421.6
Amortization of the difference between MCBC contributed cost basis and proportional share of the underlying equity in net assets of MillerCoors				4.6		4.9		35.4
Share-based compensation adjustment				0.8	[2]	5.8	[2]	0.9	[2]
Equity income in MillerCoors	539.0	510.9	457.9	539.0		510.9		457.9
Restructuring charges	26.8	34.9	2.7	17.2
Asset write-offs				2.6
Impairment of finite-lived intangible assets								$ 60.0

[1] Fiscal year 2013 includes special charges related to restructuring activities and asset write-offs of $17.2 million and $2.6 million, respectively. Fiscal year 2012 includes special charges of $31.8 million primarily due to the write-down of assets related to discontinuing the production of the Home Draft package in the U.S. and the write-down of information systems assets related to a business transformation project. Fiscal year 2011 includes special charges of $60.0 million for a write-down in the value of the Sparks brand and a $50.9 million charge resulting from the planned assumption of the Milwaukee Brewery Worker's Pension Plan, an under-funded multi-employer pension plan, as well as charges related to consulting, relocation and other integration costs.

[2] The net adjustment is to record all share-based compensation associated with pre-existing equity awards to be settled in Class B common stock held by former employees now employed by MillerCoors and to eliminate all share-based compensation impacts related to pre-existing SABMiller equity awards held by former Miller employees now employed by MillerCoors. As of the end of the second quarter of 2011, the share-based awards granted to former CBC employees now employed by MillerCoors became fully vested. As such, no further adjustments will be recorded related to these awards. We are still recording adjustments to eliminate the impacts related to the pre-existing SABMiller equity awards, which represent the amounts recorded in 2013 and 2012.