Quarterly Financial Information (Unaudited) Quarterly Financial Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								6 Months Ended	12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Sales	$ 2,901.9	$ 1,337.7	$ 1,407.0	$ 950.8	$ 1,236.9	$ 1,454.3	$ 1,433.0	$ 1,003.2		$ 6,597.4	$ 5,127.4	$ 5,927.5
Excise taxes	(607.9)	(390.1)	(420.8)	(293.6)	(392.5)	(436.9)	(427.3)	(303.2)		(1,712.4)	(1,559.9)	(1,781.2)
Net sales	2,294.0	947.6	986.2	657.2	844.4	1,017.4	1,005.7	700.0		4,885.0	3,567.5	4,146.3
Cost of goods sold	(1,485.6)	(541.3)	(562.2)	(414.0)	(542.9)	(585.9)	(579.9)	(454.8)		(3,003.1)	(2,163.5)	(2,493.3)
Gross profit	808.4	406.3	424.0	243.2	301.5	431.5	425.8	245.2		1,881.9	1,404.0	1,653.0
Amounts attributable to MCBC
Net income (loss) from continuing operations	1,438.9	202.5	174.1	163.2	33.4	13.7	229.3	79.2		1,978.7	355.6	513.5
Income (loss) from discontinued operations, net of tax	(0.5)	0.0	(1.8)	(0.5)	(0.6)	2.9	(0.3)	1.9		(2.8)	3.9	0.5
Net income (loss) attributable to Molson Coors Brewing Company	$ 1,438.4	$ 202.5	$ 172.3	$ 162.7	$ 32.8	$ 16.6	$ 229.0	$ 81.1	$ 335.0	$ 1,975.9	$ 359.5	$ 514.0
Basic net income (loss) attributable to Molson Coors Brewing Company per share
From continuing operations (in dollars per share)	$ 6.70	$ 0.94	$ 0.81	$ 0.80	$ 0.18	$ 0.07	$ 1.23	$ 0.43		$ 9.33	$ 1.92	$ 2.78
From discontinued operations (in dollars per share)	0.00	0.00	(0.01)	0.00	0.00	0.02	0.00	0.01		(0.01)	0.02	0.00
Basic net income per share (in dollars per share)	6.70	0.94	0.80	0.80	0.18	0.09	1.23	0.44	$ 1.60	9.32	1.94	2.78
Diluted net income (loss) attributable to Molson Coors Brewing Company per share
From continuing operations (in dollars per share)	6.65	0.94	0.81	0.80	0.18	0.07	1.23	0.42		9.27	1.91	2.76
From discontinued operations (in dollars per share)	0.00	0.00	(0.01)	0.00	0.00	0.02	0.00	0.01		(0.01)	0.02	0.00
Diluted net income per share (in dollars per share)	$ 6.65	$ 0.94	$ 0.80	$ 0.80	$ 0.18	$ 0.09	$ 1.23	$ 0.43	$ 1.59	$ 9.26	$ 1.93	$ 2.76