Investments Investment in MillerCoors (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended				3 Months Ended	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013	Dec. 29, 2012	Mar. 31, 2014	Dec. 31, 2013		Dec. 31, 2012
Schedule of Equity Method Investments [Line Items]
Total special items	$ 324.4		$ 200.0	$ 81.4
Results Of Operations
Restructuring Charges	14.2		26.8	34.9
Modelo
Schedule of Equity Method Investments [Line Items]
Amortization of the difference between MCBC contributed cost basis and proportionate share of the underlying equity in net assets of MillerCoors					4.9
Results Of Operations
Impairment of finite-lived intangible assets					40.5
MillerCoors
Schedule of Equity Method Investments [Line Items]
Amortization of the difference between MCBC contributed cost basis and proportionate share of the underlying equity in net assets of MillerCoors	4.6					4.6		4.9
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%
Condensed balance sheets
Current assets	795.3		798.4			798.4
Non-current assets	9,047.4		8,989.3			8,989.3
Total assets	9,842.7		9,787.7			9,787.7
Current liabilities	1,061.3		950.1			950.1
Non-current liabilities	1,578.8		1,346.2			1,346.2
Total liabilities	2,640.1		2,296.3			2,296.3
Noncontrolling interests	23.5		20.7			20.7
Owners' equity	7,179.1		7,470.7			7,470.7
Total liabilities and equity	9,842.7		9,787.7			9,787.7
Results Of Operations
Net sales	7,848.4					7,800.8		7,761.1
Cost of goods sold	(4,743.8)					(4,723.7)		(4,689.7)
Gross profit	3,104.6					3,077.1		3,071.4
Operating income	1,347.3	[1]				1,287.4	[1]	1,211.1	[1]
Net income attributable to MillerCoors	1,326.2	[1]				1,270.5	[1]	1,190.9	[1]
Impairment of finite-lived intangible assets								31.8
Restructuring Charges	$ 1.4					$ 17.2
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%

[1] Results for 2014 include special charges related to restructuring activities of $1.4 million. Results for 2013 include special charges related to restructuring activities and asset write-offs of $17.2 million and $2.6 million, respectively. Results for 2012 include 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.