Derivative Instruments and Hedging Activities Narrative (Details)				1 Months Ended					6 Months Ended	3 Months Ended										3 Months Ended
	Jun. 30, 2012 USD ($)	Dec. 31, 2011 USD ($)	Jun. 30, 2007 USD ($)	Sep. 30, 2011 Cash Flow Hedging [Member] Cross currency swaps USD ($)	Jun. 30, 2012 Cash Flow Hedging [Member] Cross currency swaps USD ($)	Jun. 30, 2012 Cash Flow Hedging [Member] Cross currency swaps GBP (£)	Apr. 10, 2007 Cash Flow Hedging [Member] Cross currency swaps CAD	Apr. 10, 2007 Cash Flow Hedging [Member] Cross currency swaps GBP (£)	Jun. 30, 2012 Scenario, Forecast [Member] USD ($) M	Jun. 30, 2012 Senior Notes [Member] USD ($)	May 03, 2012 Senior Notes [Member] USD ($)	Jun. 30, 2012 Molson Coors Central Europe (MCCE) [Member]	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 Fair Value, Inputs, Level 3 [Member] Molson Coors Central Europe (MCCE) [Member] Debt, Conversion Feature USD ($)	Jun. 15, 2012 Fair Value, Inputs, Level 3 [Member] Molson Coors Central Europe (MCCE) [Member] Debt, Conversion Feature EUR (€)	Jun. 30, 2012 Treasury Lock Loss [Member] Interest Rate Contract USD ($)
Schedule of Trading Securities and Other Trading Assets
Debt Instrument, Face Amount			$ 575,000,000								$ 1,900,000,000
Business Acquisition, Pro Forma Adjustments																				39,200,000
Proceeds from Issuance of Senior Long-term Debt										1,880,700,000
Business Acquisition, Cost of Acquired Entity, Liabilities Incurred													3,400,000,000	2,700,000,000	585,000,000	[1]	500,000,000
Stock Available, Shares, Upon Conversion of Convertible Securities												12,894,044
Derivative Liabilities																		15,200,000	12,100,000
Derivative, Notional Amount					774,000,000	530,000,000	1,200,000,000	530,000,000
Derivatives Percentage Of Derivatives Settled				25.00%
Swap transaction, principal paid						132,400,000
Derivative Liability Outstanding Amount Estinguished				98,700,000	110,600,000
Derivative Liability, Fair Value, Net					208,600,000
Credit risk adjustment, accumulated net increase (decrease) to other comprehensive income	1,300,000	1,100,000
Unrealized Gain (Loss) on Interest Rate Cash Flow Hedges, Pretax, Accumulated Other Comprehensive Income (Loss)									$ 2,100,000
Term for Expected Losses Recorded in Accumulated Other Comprehensive Income									12
Maximum Length of Time Hedged in Cash Flow Hedge									3

[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.