Debt Narrative (Details)						3 Months Ended		6 Months Ended				3 Months Ended		6 Months Ended			3 Months Ended		3 Months Ended		3 Months Ended					3 Months Ended		3 Months Ended																		0 Months Ended			3 Months Ended	6 Months Ended	0 Months Ended													3 Months Ended
	Jun. 30, 2012 USD ($)		Dec. 31, 2011 USD ($)		Jun. 30, 2007 USD ($)	Jun. 30, 2012 Senior Notes [Member] USD ($)	Jun. 25, 2011 Senior Notes [Member] USD ($)	Jun. 30, 2012 Senior Notes [Member] USD ($)	Jun. 25, 2011 Senior Notes [Member] USD ($)	May 03, 2012 Senior Notes [Member] USD ($)	Jun. 30, 2012 Senior Notes [Member] Senior Notes due 2012 $850 million 6.375% [Member] USD ($)	Jun. 30, 2012 Senior Notes [Member] $575 million 2.5% convertible Senior Notes due 2013 USD ($)	Jun. 25, 2011 Senior Notes [Member] $575 million 2.5% convertible Senior Notes due 2013 USD ($)	Jun. 30, 2012 Senior Notes [Member] $575 million 2.5% convertible Senior Notes due 2013 USD ($)	Jun. 25, 2011 Senior Notes [Member] $575 million 2.5% convertible Senior Notes due 2013 USD ($)	Dec. 31, 2011 Senior Notes [Member] $575 million 2.5% convertible Senior Notes due 2013 USD ($)	Jun. 30, 2012 Senior Notes [Member] 2.0% Interest Rate, Maturing 2017 [Member] USD ($)	May 03, 2012 Senior Notes [Member] 2.0% Interest Rate, Maturing 2017 [Member]	Jun. 30, 2012 Senior Notes [Member] 3.5% Interest Rate, Maturing 2022 [Member] USD ($)	May 03, 2012 Senior Notes [Member] 3.5% Interest Rate, Maturing 2022 [Member]	Jun. 30, 2012 Senior Notes [Member] 5.0% Interest Rate, Maturing 2042 [Member] USD ($)	May 03, 2012 Senior Notes [Member] 5.0% Interest Rate, Maturing 2042 [Member]	Jun. 30, 2012 Senior Notes [Member] Series A notes due 2017 CAD 500 million 3.95% [Member] USD ($)	May 03, 2012 Senior Notes [Member] Series A notes due 2017 CAD 500 million 3.95% [Member]	Oct. 06, 2010 Senior Notes [Member] Series A notes due 2017 CAD 500 million 3.95% [Member] CAD	Jun. 30, 2012 Term Loan Agreement [Member] years	Apr. 03, 2012 Term Loan Agreement [Member] USD ($)	Jun. 30, 2012 Line of Credit [Member] years	Jun. 30, 2012 Line of Credit [Member] Revolving Multicurrency Bank Credit Facility [Member] USD ($)	Jun. 25, 2011 Line of Credit [Member] Revolving Multicurrency Bank Credit Facility [Member] USD ($)	Jun. 30, 2012 Revolving Credit [Member] USD ($)	Apr. 03, 2012 Revolving Credit [Member] USD ($)	Jun. 30, 2012 Other Debt Obligations [Member] $575 million 2.5% convertible Senior Notes due 2013 USD ($)	Dec. 31, 2011 Other Debt Obligations [Member] $575 million 2.5% convertible Senior Notes due 2013 USD ($)	Apr. 03, 2012 Tranch 1 [Member] Term Loan Agreement [Member] USD ($)	Apr. 03, 2012 Tranch 2 [Member] Term Loan Agreement [Member] USD ($)	Apr. 03, 2012 Tranch 2 [Member] Term Loan Agreement [Member] EUR (€)	Jun. 30, 2012 Molson Coors Central Europe (MCCE) [Member] USD ($)	Jun. 15, 2012 Molson Coors Central Europe (MCCE) [Member] USD ($)	Jun. 15, 2012 Molson Coors Central Europe (MCCE) [Member] EUR (€)	Jun. 15, 2012 Molson Coors Central Europe (MCCE) [Member] Senior Notes [Member] USD ($)		Jun. 15, 2012 Molson Coors Central Europe (MCCE) [Member] Senior Notes [Member] EUR (€)	Jun. 15, 2012 Molson Coors Central Europe (MCCE) [Member] Convertible Debt [Member] USD ($)		Jun. 30, 2012 Molson Coors Central Europe (MCCE) [Member] Convertible Debt [Member] Zero Coupon Senior Unsecured Note [Member] USD ($)	Jun. 15, 2012 Molson Coors Central Europe (MCCE) [Member] Convertible Debt [Member] Zero Coupon Senior Unsecured Note [Member] USD ($)	Jun. 15, 2012 Molson Coors Central Europe (MCCE) [Member] Convertible Debt [Member] Zero Coupon Senior Unsecured Note [Member] EUR (€)	Jun. 30, 2012 Molson Coors Central Europe (MCCE) [Member] Convertible Debt [Member] Zero Coupon Senior Unsecured Note [Member] USD ($)	Jun. 30, 2012 Molson Coors Central Europe (MCCE) [Member] Convertible Debt [Member] Zero Coupon Senior Unsecured Note [Member] USD ($)	Jun. 30, 2012 Equity conversion feature of debt Molson Coors Central Europe (MCCE) [Member] Convertible Debt [Member] Zero Coupon Senior Unsecured Note [Member] USD ($)	Jun. 30, 2012 Factoring Arrangements [Member] Molson Coors Central Europe (MCCE) [Member] USD ($)	Jun. 30, 2012 Line of Credit, Japanese YEN [Member] Line of Credit [Member] USD ($)	Dec. 31, 2011 Line of Credit, Japanese YEN [Member] Line of Credit [Member] USD ($)	Jun. 30, 2012 Fair Value, Inputs, Level 3 [Member] USD ($)	Mar. 31, 2012 Fair Value, Inputs, Level 3 [Member] USD ($)	Jun. 30, 2012 Fair Value, Inputs, Level 3 [Member] Debt [Member] USD ($)	Jun. 15, 2012 Fair Value, Inputs, Level 3 [Member] Debt [Member] Molson Coors Central Europe (MCCE) [Member] USD ($)	Jun. 15, 2012 Fair Value, Inputs, Level 3 [Member] Debt [Member] Molson Coors Central Europe (MCCE) [Member] EUR (€)	Jun. 30, 2012 Fair Value, Inputs, Level 1 [Member] USD ($)	Dec. 31, 2011 Fair Value, Inputs, Level 1 [Member] USD ($)	Jun. 30, 2012 Fair Value, Inputs, Level 2 [Member] USD ($)	Dec. 31, 2011 Fair Value, Inputs, Level 2 [Member] USD ($)	Jun. 30, 2012 Bridge Facility Fees [Member] Bridge Loan [Member] USD ($)	Jun. 30, 2012 Treasury Lock Loss [Member] Interest Rate Contract [Member] USD ($)	Jun. 30, 2012 Issuer 2002 [Member] Senior Notes [Member] Senior Notes due 2012 $850 million 6.375% [Member] USD ($) years	May 07, 2002 Issuer 2002 [Member] Senior Notes [Member] Senior Notes due 2012 $850 million 6.375% [Member]
Debt Instrument [Line Items]
Repayments of Long-term Debt																																																																		$ 850,000,000
Debt Instrument, Interest Rate, Stated Percentage											6.375%	2.50%		2.50%				2.00%		3.50%		5.00%	3.95%	3.95%	3.95%																					0.00%			0.00%	0.00%																	6.375%
Debt Instrument, Principal Amount, Per Share													1,000		1,000
Debt Instrument, Convertible Conversion Price Per Share												$ 54.76	$ 52.79	$ 54.76	$ 52.79
Percentage of Premium over Stock Price of Convertible Debt													25.00%		25.00%
Debt Instrument, Convertible Number of Equity Instruments, Ratio												18.263	18.9441	18.263	18.9441
Interest Expense Debt Amortization						4,500,000	4,400,000	9,000,000	8,700,000
Interest Expense, Debt												3,600,000	3,600,000	7,300,000	7,200,000
Debt Instruments, Interest Rate Effective Percentage												5.83%	5.91%	5.84%	5.92%
Debt Instrument, Convertible, Carrying Amount of Equity Component												103,900,000		103,900,000
Debt Instrument, Convertible Carrying Amount of the Equity Component, Net of Tax												64,200,000		64,200,000
Debt Instrument, Unamortized Discount												19,900,000		19,900,000		28,900,000																	7,600,000	1,900,000
Debt Instrument, Face Amount					575,000,000					1,900,000,000	850,000,000		575,000,000		575,000,000								500,000,000		500,000,000		300,000,000					300,000,000			150,000,000	150,000,000	120,000,000
Noncash Interest Expense Due to Amortization of Unamortized Debt Discount in Future Periods Convertible Debt Estimated Range Low														9,000,000
Noncash Interest Expense Due to Amortization of Unamortized Debt Discount in Future Periods Convertible Debt Estimated Range High														11,000,000
Business Acquisition, Cost of Acquired Entity, Liabilities Incurred																																							3,400,000,000	2,700,000,000	585,000,000	[1]	500,000,000	645,900,000	[2]			500,000,000
Stock Available, Shares, Upon Conversion of Convertible Securities																																						12,894,044
Derivative Liabilities																																																										15,200,000	12,100,000
Discounts to Long-term Debt						4,600,000																																									1,300,000	1,000,000
Long-term Debt	4,781,000,000		1,959,600,000																																											632,200,000			632,200,000	632,200,000
Derivative Financial Instruments, Liabilities, Fair Value Disclosure																																																			20,800,000				20,800,000	0	20,800,000
Interest Expense, Other																																																			5,600,000
Amortization of Debt Discount (Premium)																																														100,000
Debt Instrument, Convertible, Effective Interest Rate																																																	0.25%	0.25%
Proceeds from Issuance of Senior Long-term Debt						1,880,700,000											300,000,000		500,000,000		1,100,000,000
Underwriting Fees Related to Long-term Debt						14,700,000
Debt Issuance Costs, Capitalized										18,000,000																	3,000,000					5,000,000
Business Acquisition, Pro Forma Adjustments																																																																13,000,000	39,200,000
Debt Instrument, Term																										4		4																																						10
Long-term Debt, Quarterly Installment Payments, Percentage of Initial Principal Obligation																											2.50%
Long-term Debt, Lump Sum Payment Due Following Installments, Percent of Principal Obligation																											62.50%
Revolving credit facility, maximum borrowing capacity																														400,000,000		550,000,000
Amount of revolving multicurrency bank credit facility that was terminated																														750,000,000
Term of credit facility (in years)																														4
Additional capacity for letters of credit																														100,000,000
Line of Credit Facility, Current Borrowing Capacity	0	[3]	0	[3]																									0		0
Debt issuance costs capitalized																														2,200,000
Short-term borrowings	119,400,000		2,200,000																																																	9,300,000	6,300,000	2,200,000
Bank Overdrafts																																						103,800,000
Cash and Due from Banks																																						116,200,000
Cash and Cash Equivalents, Net of Bank Overdrafts																																						12,400,000
Long-term Debt, Fair Value	5,052,600,000		2,133,600,000																																																									2,602,100,000	608,500,000
Debt Instrument, Fair Value Disclosure																																																														$ 2,148,300,000	$ 1,525,100,000

[1] 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.

[2] 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.

[3] On April 3, 2012, we also entered into a revolving credit agreement (the ''Credit Agreement''). The Credit Agreement provides for a 4-year revolving credit facility of $300 million that was subsequently amended to increase the borrowing limit to $550 million. The Credit Agreement contains customary events of default and specified representations and warranties and covenants, including, among other things, covenants that limit our and our subsidiaries' ability to incur certain additional priority indebtedness, create or permit liens on assets, or engage in mergers or consolidations. Debt issuance costs capitalized in connection with the Credit Agreement will be amortized over the life of the facility and total approximately $5 million. There were no outstanding borrowings on our $550 million credit facility as of June 30, 2012. During the second quarter of 2011, we terminated our $750 million revolving multicurrency bank credit facility, which was scheduled to expire in August 2011. Additionally, in connection with this termination, we entered into an agreement for a 4-year revolving multicurrency credit facility of $400 million in the second quarter of 2011, which provides a $100 million sub-facility available for the issuance of letters of credit. We incurred $2.2 million of issuance costs and up-front fees related to this agreement, which are being amortized over the term of the facility. There were no outstanding borrowings on the $400 million credit facility as of June 30, 2012.