Unusual or Infrequent Items Summary Special Items (Details) (USD $) In Millions	3 Months Ended				9 Months Ended
	Sep. 24, 2011		Sep. 25, 2010		Sep. 24, 2011		Sep. 25, 2010
Restructuring Cost and Reserve [Line Items]
Total special items	$ 0.1		$ 3.1		$ 11.1		$ 21.5
Canada | Restructuring, exit and other related costs associated with the Edmonton and Montreal breweries
Restructuring Cost and Reserve [Line Items]
Total special items	0	[1]	0	[1]	0.6	[1]	0.9	[1]
Canada | Special termination benefits
Restructuring Cost and Reserve [Line Items]
Total special items	0.7	[2]	0	[2]	4.7	[2]	3.2	[2]
Canada | Flood insurance reimbursement
Restructuring Cost and Reserve [Line Items]
Total special items	(0.4)	[3]			(0.3)	[3]
Canada | Software abandonment
Restructuring Cost and Reserve [Line Items]
Total special items			0.4	[4]			12.8	[4]
Canada | BRI Loan Guarantee Adjustment
Restructuring Cost and Reserve [Line Items]
Total special items	0	[5]	0	[5]	(2.0)	[5]	0	[5]
Canada | Fixed asset adjustment
Restructuring Cost and Reserve [Line Items]
Total special items	0	[6]	0	[6]	7.6	[6]	0	[6]
U.K. | Restructuring charge
Restructuring Cost and Reserve [Line Items]
Total special items	(0.5)	[7]	2.4	[7]	2.2	[7]	3.6	[7]
U.K. | Release of non-income-related tax reserve
Restructuring Cost and Reserve [Line Items]
Total special items	0	[8]	0	[8]	(2.5)	[8]	0.4	[8]
U.K. | Other.
Restructuring Cost and Reserve [Line Items]
Total special items	0.1	[9]	0	[9]	0.1	[9]	(0.3)	[9]
MCI and Corporate | Costs associated with outsourcing and other strategic initiatives
Restructuring Cost and Reserve [Line Items]
Total special items	$ 0.2	[10]	$ 0.3	[10]	$ 0.7	[10]	$ 0.9	[10]

[1] During the second quarter of 2011 and the first half of 2010, we recognized expenses for restructuring costs associated with employee terminations and impairment of assets at the Montreal and Edmonton breweries.

[2] During the first three quarters of 2011, we recognized charges related to special termination benefits offered to eligible employees upon election for early retirement as collective bargaining agreements were ratified with MCC impacting the Quebec Hourly Defined Benefit pension plan. Additionally, during the first quarter of 2011 and the first half of 2010, we recognized expenses for special termination benefits related to the Ontario-Atlantic Hourly Defined Benefit pension plan.

[3] During the third quarter of 2011, we received insurance proceeds in excess of expenses incurred related to flood damages at our Toronto offices, which was partially offset by expenses incurred in the first three quarters of 2011.

[4] During the second quarter and third quarter of 2010, a capital asset write-off was recorded related to abandonment of sales support software, which had been under development, as a result of a change in strategic direction relative to the use of the software.

[5] During the second quarter of 2011, we recognized a $2.0 million gain resulting from a reduction of our guarantee of Brewers' Retail, Inc. ("BRI") debt obligations, which is discussed further in Note 15 "Commitments and Contingencies".

[6] During the second quarter of 2011, we recognized a $7.6 million loss related to the correction of an error in prior periods to reduce fixed assets in the Canada segment, resulting from the performance of a fixed asset count. The impact of the error and the related correction this year is not material to any prior annual or interim financial statements and is not material to the expected full year results for this fiscal year.

[7] During the third quarter of 2011, a benefit was realized from an adjustment to a supply chain restructuring accrual. During the first three quarters of 2011 and the first three quarters of 2010, we recognized employee termination costs related to supply chain restructuring activity and company-wide efforts to increase efficiency in certain operations, finance, information technology and human resource activities.

[8] During 2009, we established a non-income-related tax reserve of $10.4 million that was recorded as a special item. The amount recorded in the first quarter of 2011 represents a release of a portion of this reserve.

[9] During the third quarter of 2011, we recognized costs related to the integration of our Sharp's Brewery Ltd. acquisition. During the first half of 2010, we recognized a gain due to the release of an accrual of $0.3 million related to a potential repayment of a government grant.

[10] During the second quarter and third quarter of 2011 and the first three quarters of 2010, we recognized costs related to the acquisition and integration of our China and India joint ventures.