Special items Summary Special Items (Details) (USD $)	3 Months Ended				12 Months Ended
	Mar. 30, 2013 Employees		Mar. 31, 2012		Dec. 26, 2009
Restructuring Cost and Reserve [Line Items]
Restructuring Related Reduction in Employees	660
Total special items	$ 1,500,000		$ 1,500,000
Non-income-related Tax Reserves					10,400,000
Gain (Loss) Related to Restructuring Reserve Low End of Range	0
Gain (Loss) Related to Restructuring Reserve High End of Range	22,300,000
Canada [Member] | Restructuring, exit and other related costs associated with the Edmonton and Montreal breweries
Restructuring Cost and Reserve [Line Items]
Total special items	1,300,000	[1]	1,600,000	[1]
Canada [Member] | Special termination benefits
Restructuring Cost and Reserve [Line Items]
Total special items	800,000	[2]	500,000	[2]
Europe [Member] | Restructuring charge
Restructuring Cost and Reserve [Line Items]
Total special items	3,300,000	[1]	1,800,000	[1]
Europe [Member] | Release of non-income-related tax reserve
Restructuring Cost and Reserve [Line Items]
Total special items	(4,200,000)	[3]	(3,500,000)	[3]
Corporate | Restructuring charge
Restructuring Cost and Reserve [Line Items]
Total special items	$ 300,000	[1]	$ 1,100,000	[1]

[1] During 2013 and 2012, we recognized expenses associated with restructuring programs focused on labor savings and organizational effectiveness across all functions. As a result, we have reduced headcount by approximately 660 employees since the start of 2012.

[2] During the first quarters of 2013 and 2012, we recognized charges related to special termination benefits as eligible employees elected early retirement offered as a result of the ratification of Collective Bargaining Agreements with MCC's brewery groups.

[3] During 2009, we established a non-income-related tax reserve of $10.4 million that was recorded as a special item. Our estimates indicated a range of possible loss relative to this reserve of zero to $22.3 million, inclusive of potential penalties and interest. The amounts recorded in 2013 and 2012 represent the release of this reserve as a result of a change in estimate. As a result, this non-income-related tax reserve is fully released as of March 30, 2013.