Basis of Presentation and Summary of Significant Accounting Policies Change in Accounting Policy (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 30, 2013		Mar. 31, 2014 Canada [Member]	Mar. 30, 2013 Canada [Member]		Mar. 31, 2014 U.S. [Member]	Mar. 30, 2013 U.S. [Member]		Mar. 31, 2014 Europe [Member]	Mar. 30, 2013 Europe [Member]		Mar. 31, 2014 MCI [Member]	Mar. 30, 2013 MCI [Member]		Mar. 31, 2014 Corporate [Member]	Mar. 30, 2013 Corporate [Member]		Dec. 31, 2013 As Reported [Member]	Sep. 28, 2013 As Reported [Member]	Jun. 29, 2013 As Reported [Member]	Mar. 30, 2013 As Reported [Member]	Dec. 31, 2013 As Reported [Member] Canada [Member]	Sep. 28, 2013 As Reported [Member] Canada [Member]	Jun. 29, 2013 As Reported [Member] Canada [Member]	Mar. 30, 2013 As Reported [Member] Canada [Member]	Dec. 31, 2013 As Reported [Member] U.S. [Member]	Sep. 28, 2013 As Reported [Member] U.S. [Member]	Jun. 29, 2013 As Reported [Member] U.S. [Member]	Mar. 30, 2013 As Reported [Member] U.S. [Member]	Dec. 31, 2013 As Reported [Member] Europe [Member]	Sep. 28, 2013 As Reported [Member] Europe [Member]	Jun. 29, 2013 As Reported [Member] Europe [Member]	Mar. 30, 2013 As Reported [Member] Europe [Member]	Dec. 31, 2013 As Reported [Member] MCI [Member]	Sep. 28, 2013 As Reported [Member] MCI [Member]	Jun. 29, 2013 As Reported [Member] MCI [Member]	Mar. 30, 2013 As Reported [Member] MCI [Member]	Dec. 31, 2013 As Reported [Member] Corporate [Member]	Sep. 28, 2013 As Reported [Member] Corporate [Member]	Jun. 29, 2013 As Reported [Member] Corporate [Member]	Mar. 30, 2013 As Reported [Member] Corporate [Member]	Dec. 31, 2013 As Adjusted [Member]	Sep. 28, 2013 As Adjusted [Member]	Jun. 29, 2013 As Adjusted [Member]	Mar. 30, 2013 As Adjusted [Member]	Dec. 31, 2013 As Adjusted [Member] Canada [Member]	Sep. 28, 2013 As Adjusted [Member] Canada [Member]	Jun. 29, 2013 As Adjusted [Member] Canada [Member]	Mar. 30, 2013 As Adjusted [Member] Canada [Member]	Dec. 31, 2013 As Adjusted [Member] U.S. [Member]	Sep. 28, 2013 As Adjusted [Member] U.S. [Member]	Jun. 29, 2013 As Adjusted [Member] U.S. [Member]	Mar. 30, 2013 As Adjusted [Member] U.S. [Member]	Dec. 31, 2013 As Adjusted [Member] Europe [Member]	Sep. 28, 2013 As Adjusted [Member] Europe [Member]	Jun. 29, 2013 As Adjusted [Member] Europe [Member]	Mar. 30, 2013 As Adjusted [Member] Europe [Member]	Dec. 31, 2013 As Adjusted [Member] MCI [Member]	Sep. 28, 2013 As Adjusted [Member] MCI [Member]	Jun. 29, 2013 As Adjusted [Member] MCI [Member]	Mar. 30, 2013 As Adjusted [Member] MCI [Member]	Dec. 31, 2013 As Adjusted [Member] Corporate [Member]	Sep. 28, 2013 As Adjusted [Member] Corporate [Member]	Jun. 29, 2013 As Adjusted [Member] Corporate [Member]	Mar. 30, 2013 As Adjusted [Member] Corporate [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Marketing, general and administrative expenses	$ (263.9)	$ (293.9)																	$ (296.4)	$ (307.8)	$ (304.3)	$ (285.3)																					$ (289.6)	$ (290.8)	$ (319.5)	$ (293.9)
Income (loss) from continuing operations before income taxes	169.6	32.8	[1]	88.3	28.4	[1]	122.8	117.4	[1]	27.0	(5.2)	[1]	(3.0)	(5.2)	[1]	(65.5)	(102.6)	[1]	145.3	155.4	312.4	41.4	60.9	128.7	137.3	36.4	100.7	148.3	172.6	117.4	25.9	(69.5)	81.6	(3.7)	0	(2.4)	(3.3)	(6.1)	(42.2)	(49.7)	(75.8)	(102.6)	152.1	172.4	297.2	32.8	62.7	143.6	128.6	28.4	100.7	148.3	172.6	117.4	31.1	(67.4)	75.8	(5.2)	(0.2)	(2.4)	(4.0)	(5.2)	(42.2)	(49.7)	(75.8)	(102.6)
Income tax benefit (expense)	(4.8)	(2.0)																	(13.7)	(32.7)	(34.1)	(3.5)																					(14.8)	(37.2)	(30.0)	(2.0)
Net income (loss) attributable to Molson Coors Brewing Company	$ 163.4	$ 28.5	[1]																$ 131.5	$ 121.8	$ 278.4	$ 35.6																					$ 137.2	$ 134.3	$ 267.3	$ 28.5
Diluted net income (loss) attributable to Molson Coors Brewing Company per share	$ 0.88	$ 0.16	[1]																$ 0.71	$ 0.66	$ 1.51	$ 0.20																					$ 0.74	$ 0.73	$ 1.45	$ 0.16

[1] Amounts have been adjusted to reflect the change in interim accounting for advertising expenses. See Note 1, "Basis of Presentation and Summary of Significant Accounting Policies" for further discussion.