Derivative Instruments and Hedging Activities Narrative (Details)	0 Months Ended	12 Months Ended			12 Months Ended						12 Months Ended							12 Months Ended			0 Months Ended	1 Months Ended							0 Months Ended			12 Months Ended		0 Months Ended								12 Months Ended
	Dec. 31, 2014 USD ($)	Dec. 29, 2012 USD ($)	Dec. 31, 2014 Interest rate swaps USD ($)	Dec. 31, 2014 Forward Starting Interest Rate Swap CAD	Dec. 31, 2014 Foreign Exchange Forward [Member]	Dec. 31, 2014 Natural Gas [Member]	Dec. 31, 2014 Aluminum [Member]	Dec. 31, 2014 Corn [Member]	Oct. 06, 2010 Forward Contracts [Member] CAD	Sep. 22, 2005 Forward Contracts [Member] CAD	Dec. 31, 2014 Diesel	Dec. 31, 2014 Fair Value Hedging USD ($)	Dec. 31, 2014 Net Investment Hedges USD ($)	Dec. 31, 2013 Net Investment Hedges USD ($)	Dec. 29, 2012 Net Investment Hedges USD ($)	Dec. 31, 2014 Net Investment Hedges Cross currency swaps USD ($)	Apr. 10, 2007 Net Investment Hedges Cross currency swaps CAD	Dec. 31, 2014 Cash Flow Hedges USD ($)	Dec. 31, 2013 Cash Flow Hedges USD ($)	Dec. 29, 2012 Cash Flow Hedges USD ($)	Jan. 03, 2014 Cash Flow Hedges Cross currency swaps USD ($)	Sep. 30, 2011 Cash Flow Hedges Cross currency swaps USD ($)	Jan. 03, 2014 Cash Flow Hedges Cross currency swaps CAD	Mar. 31, 2012 Cash Flow Hedges Cross currency swaps USD ($)	Sep. 30, 2011 Cash Flow Hedges Cross currency swaps GBP (£)	Apr. 10, 2007 Cash Flow Hedges Cross currency swaps USD ($)	Apr. 10, 2007 Cash Flow Hedges Cross currency swaps CAD	Apr. 10, 2007 Cash Flow Hedges Cross currency swaps GBP (£)	Apr. 03, 2012 Term Loan Agreement	May 03, 2012 Senior Notes USD ($)	Oct. 06, 2010 Senior Notes USD ($)	Dec. 29, 2012 Treasury Lock Loss Interest Rate Contract USD ($)	Dec. 31, 2014 Convertible Senior Unsecured Note Due 2013 €500 Million 0.0% [Member] Senior Notes	May 03, 2012 Convertible Senior Unsecured Note Due 2013 €500 Million 0.0% [Member] Treasury Lock Loss Interest Rate Contract	Sep. 03, 2013 Convertible Senior Unsecured Note Due 2013 €500 Million 0.0% [Member] Molson Coors Central Europe (MCCE) Convertible Debt USD ($)	Sep. 03, 2013 Convertible Senior Unsecured Note Due 2013 €500 Million 0.0% [Member] Molson Coors Central Europe (MCCE) Convertible Debt EUR (€)	Aug. 13, 2013 Convertible Senior Unsecured Note Due 2013 €500 Million 0.0% [Member] Molson Coors Central Europe (MCCE) Convertible Debt EUR (€)	Dec. 31, 2014 $500 million 3.5% notes due 2022 Senior Notes	May 03, 2012 $500 million 3.5% notes due 2022 Senior Notes USD ($)	Apr. 03, 2012 Tranch 2 Term Loan Agreement USD ($)	Apr. 03, 2012 Tranch 2 Term Loan Agreement EUR (€)	Dec. 31, 2014 Interest expense, net Fair Value Hedging Interest rate swaps USD ($)	Dec. 31, 2014 Interest expense, net Cash Flow Hedges Interest rate swaps USD ($)	Dec. 31, 2013 Interest expense, net Cash Flow Hedges Interest rate swaps USD ($)	Dec. 29, 2012 Interest expense, net Cash Flow Hedges Interest rate swaps USD ($)	Dec. 31, 2014 Interest rate swaps $500 million 3.5% notes due 2022 Senior Notes USD ($)	Dec. 31, 2014 Forward Starting Interest Rate Swap	Jan. 27, 2015 Subsequent event Forward Starting Interest Rate Swap CAD
Schedule of Trading Securities and Other Trading Assets
Debt instrument, face amount									500,000,000	900,000,000																				$ 1,900,000,000	$ 500,000,000								$ 500,000,000	$ 150,000,000	€ 120,000,000
Change in unrealized gain (loss) on hedged item in fair value hedge												10,800,000																														10,800,000
Increase in fair value of hedged item in interest rate fair value hedge																																														10,800,000
Business acquisition, pro forma adjustments																																39,200,000
Convertible debt, shares issued upon conversion																																		12,894,044
Convertible debt, settlement of conversion feature																																			14,400,000	10,900,000	10,900,000
Debt instrument, term																													4 years
Notional amount of derivative, not designated as hedging instrument			500,000,000	400,000,000																			241,000,000			774,000,000	1,200,000,000	530,000,000																				40,000,000
Derivative, Fixed Interest Rate																																															2.81%
Payment to settle derivative instrument																					65,200,000
Maximum term, commodity swap contract hedge					60 months	48 months	60 months	60 months			24 months
Derivatives Percentage Of Derivatives Settled																						25.00%
Loss from cash flow hedges reclassified from AOCI to earnings		6,700,000											0	0	0			(3,800,000)	5,500,000	(10,200,000)		(900,000)																					(1,500,000)	(1,600,000)	(1,600,000)
Derivative Liability Outstanding Amount Exstinguished																113,900,000	361,000,000					98,700,000		110,600,000
Swap transaction, principal paid																									132,400,000.0
Debt instrument, interest rate percentage																																	0.00%					3.50%	3.50%
Cash flow hedge loss expected to be reclassified from AOCI to income within twelve months	$ 7,000,000
Maximum length of time over which forecasted transactions are hedged																		3 years 0 months