Earnings per Share ("EPS") Antidilutive (Details) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended					3 Months Ended				6 Months Ended				3 Months Ended				6 Months Ended				3 Months Ended				6 Months Ended				3 Months Ended				6 Months Ended
	Jun. 30, 2012 USD ($)	Jun. 25, 2011	Jun. 30, 2012 USD ($)	Jun. 25, 2011	Jun. 30, 2007 USD ($)	Jun. 30, 2012 2.5% Convertible Senior Notes [Member] USD ($)	May 03, 2012 2.5% Convertible Senior Notes [Member] USD ($)	Jun. 30, 2012 Stock options, SOSARs and RSUs		Jun. 25, 2011 Stock options, SOSARs and RSUs		Jun. 30, 2012 Stock options, SOSARs and RSUs		Jun. 25, 2011 Stock options, SOSARs and RSUs		Jun. 30, 2012 Shares of Class B common stock 2.5% Convertible Senior Notes [Member]		Jun. 25, 2011 Shares of Class B common stock 2.5% Convertible Senior Notes [Member]		Jun. 30, 2012 Shares of Class B common stock 2.5% Convertible Senior Notes [Member]		Jun. 25, 2011 Shares of Class B common stock 2.5% Convertible Senior Notes [Member]		Jun. 30, 2012 Shares of Class B common stock €500 Million Convertible Notes [Member]		Jun. 25, 2011 Shares of Class B common stock €500 Million Convertible Notes [Member]		Jun. 30, 2012 Shares of Class B common stock €500 Million Convertible Notes [Member]		Jun. 25, 2011 Shares of Class B common stock €500 Million Convertible Notes [Member]		Jun. 30, 2012 Warrants to issue shares of Class B common stock		Jun. 25, 2011 Warrants to issue shares of Class B common stock		Jun. 30, 2012 Warrants to issue shares of Class B common stock		Jun. 25, 2011 Warrants to issue shares of Class B common stock		Jun. 15, 2012 Molson Coors Central Europe (MCCE) [Member] USD ($)	Jun. 15, 2012 Molson Coors Central Europe (MCCE) [Member] EUR (€)	Jun. 15, 2012 Molson Coors Central Europe (MCCE) [Member] Convertible Debt [Member] USD ($)		Jun. 15, 2012 Molson Coors Central Europe (MCCE) [Member] 2.5% Convertible Senior Notes [Member] USD ($)		Jun. 15, 2012 Molson Coors Central Europe (MCCE) [Member] 2.5% Convertible Senior Notes [Member] EUR (€)	Jun. 30, 2012 Convertible Senior Notes Due 2013 $575 Million 2.5% [Member] 2.5% Convertible Senior Notes [Member]	Jun. 25, 2011 Convertible Senior Notes Due 2013 $575 Million 2.5% [Member] 2.5% Convertible Senior Notes [Member] USD ($)
Anti-dilutive securities:
Debt Instrument, Interest Rate, Stated Percentage																																															2.50%
Anti-dilutive security (in shares)	24.3	22.1	23.4	22.0				2.1	[1]	0.7	[1]	1.4	[1]	0.6	[1]	10.9	[2]	10.7	[2]	10.9	[2]	10.7	[2]	0.4	[3]	0	[3]	0.2	[3]	0	[3]	10.9	[2]	10.7	[2]	10.9	[2]	10.7	[2]
Debt face amount					$ 575		$ 1,900																																									$ 575
Stock price at which impact of net share settlement at conversion will begin to dilute EPS (in dollars per share)	$ 52.57		$ 52.57
Stock price at which impact of net share settlement under warrants will begin to dilute EPS (in dollars per share)	$ 67.30		$ 67.30
Stock price at which receipt of MCBC stock under purchased call options would be anti-dilutive, low end of the range (in dollars per share)	$ 52.57		$ 52.57
Stock price at which receipt of MCBC stock under purchased call options would be anti-dilutive, high end of the range (in dollars per share)	$ 67.30		$ 67.30
Senior convertible notes issued in business acquisition																																								$ 3,400.0	€ 2,700.0	$ 645.9	[4]	$ 585.0	[5]	€ 500.0
Stock Price at Which Debt Conversion Will Dilute Earnings Per Share						$ 49.12

[1] Exercise prices exceed the average market price of the common shares or are anti-dilutive due to the impact of the unrecognized compensation cost on the calculation of assumed proceeds in the application of the treasury stock method.

[2] We issued $575 million of senior convertible notes in June 2007. The impact of a net share settlement of the conversion amount at maturity will begin to dilute earnings per share if and when our stock price reaches $52.57. The impact of stock that could be issued to settle share obligations we could have under the warrants we issued simultaneously with the senior convertible notes issuance will begin to dilute earnings per share when our stock price reaches $67.30. The potential receipt of MCBC stock from counterparties under our purchased call options when and if our stock price is between $52.57 and $67.30 would be anti-dilutive and excluded from any calculations of earnings per share.

[3] Upon closing of the Acquisition in June 2012, we issued a €500 million Zero Coupon Senior Unsecured Convertible Note due 2013 to the Seller. The impact of a net share settlement of the conversion amount at maturity will begin to dilute earnings per share if and when our stock price reaches $49.12 based on foreign exchange rates at June 30, 2012. See further discussion in Note 13, "Debt."

[4] We issued a €500 million Zero Coupon Senior Unsecured Convertible Note due 2013 to the Seller upon close of the Acquisition. See Note 13, "Debt" for further discussion.

[5] According to our agreement with the Seller and in accordance with the terms of the senior debt facility agreement, upon close of the Acquisition, we immediately repaid pre-existing StarBev third-party debt including accrued interest.