Investments Investment in MillerCoors (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Sep. 24, 2011	Dec. 29, 2012 Directors	Dec. 31, 2012		Dec. 31, 2011	Dec. 31, 2011		Dec. 31, 2010	Dec. 25, 2010
Home Draft
Results Of Operations
Impairment of finite-lived intangible assets		$ 31.8
MillerCoors
Schedule of Equity Method Investments [Line Items]
Number of directors appointed		5
MCBC economic Interest (as a percent)		42.00%			42.00%	42.00%		42.00%
Voting interest shared (as a percent)		50.00%
Restriction on transferring economic or voting interest in the joint venture (in years)		5 years
Condensed balance sheets
Current assets			841.4		810.9	810.9
Non-current assets			8,949.9		8,861.7	8,861.7
Total assets			9,791.3		9,672.6	9,672.6
Current liabilities			958.5		922.7	922.7
Non-current liabilities			1,537.5		1,471.3	1,471.3
Total liabilities			2,496.0		2,394.0	2,394.0
Noncontrolling interests			28.4		36.7	36.7
Owners' equity			7,266.9		7,241.9	7,241.9
Total liabilities and equity			9,791.3		9,672.6	9,672.6
Results Of Operations
Net sales			7,761.1			7,550.2			7,570.6
Cost of goods sold			(4,689.7)			(4,647.9)			(4,686.3)
Gross profit			3,071.4			2,902.3			2,884.3
Operating income			1,211.1	[1]		1,020.3	[1]		1,078.9	[1]
Net income attributable to MillerCoors		1,190.9	1,190.9	[1]	1,003.8	1,003.8	[1]	1,057.0	1,057.0	[1]
Impairment of finite-lived intangible assets	60.0
Integration planning costs									30.3
SAB Miller
Schedule of Equity Method Investments [Line Items]
Number of directors appointed		5
MCBC economic Interest (as a percent)		58.00%
Voting interest shared (as a percent)		50.00%
Milwaukee Brewery Pension Plan [Member]
Results Of Operations
Impairment of finite-lived intangible assets						$ 50.9

[1] 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 the 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. Fiscal year 2010 includes special charges of $30.3 million primarily driven by pension curtailment losses and integration costs, including severance and relocation costs resulting from the sales office reorganization.