Acquisition of Molson Coors Central Europe - Pro Forma Results (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended				3 Months Ended		0 Months Ended	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 25, 2011	Jun. 30, 2012	Jun. 25, 2011	Jun. 30, 2012 Euro Currency Purchase Loss [Member]	Jun. 30, 2012 Fair Value Adjustment to Acquisition Date Inventory [Member]	Jun. 30, 2012 Bridge Loan [Member] Bridge Facility Fees [Member]	Jun. 30, 2012 Interest Rate Contract [Member] Treasury Lock Loss [Member]	Jun. 30, 2012 Molson Coors Central Europe (MCCE) [Member]	Jun. 30, 2012 Molson Coors Central Europe (MCCE) [Member]	Jun. 25, 2011 Molson Coors Central Europe (MCCE) [Member]	Jun. 30, 2012 Molson Coors Central Europe (MCCE) [Member]	Jun. 25, 2011 Molson Coors Central Europe (MCCE) [Member]
Business Acquisition [Line Items]
Net sales	$ 999.4	$ 933.6	$ 1,690.8	$ 1,624.0					$ 57.3
Income tax expense	123.8	268.5	220.4	367.0					12.4
Business Acquisition, Pro Forma Adjustments					57.9	8.6	13.0	39.2
Business Acquisition, Pro Forma Information
Net sales, pro forma										1,200.5	1,231.5	2,031.3	2,069.4
Inome (loss) from continuing operations before income taxes, pro forma										279.7	315.8	347.5	395.3
Net income (loss) attributable to MCBC, pro forma										$ 241.4	$ 267.3	$ 299.4	$ 336.6
Net income per common share attributable to MCBC, Basic, pro forma										$ 1.33	$ 1.43	$ 1.65	$ 1.80
Net income per common share attributable to MCBC, Diluted, pro forma										$ 1.32	$ 1.41	$ 1.64	$ 1.78