CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Sales	$ 3,625.1	$ 3,552.9	$ 10,313.6	$ 10,259.8
Excise taxes	(690.9)	(669.7)	(1,962.7)	(1,836.6)
Net Sales	2,934.2	2,883.2	8,350.9	8,423.2
Cost of Goods Sold	(1,714.0)	(1,589.1)	(4,988.8)	(4,716.9)
Gross profit	1,220.2	1,294.1	3,362.1	3,706.3
Marketing, general and administrative expenses	(713.9)	(783.8)	(2,139.7)	(2,271.5)
Special items, net	(36.6)	(4.1)	267.7	(27.3)
Operating income (loss)	469.7	506.2	1,490.1	1,407.5
Interest income (expense), net	(67.4)	(72.6)	(227.3)	(258.4)
Other pension and postretirement benefits (costs), net	7.6	9.6	27.5	32.3
Other income (expense), net	0.2	(2.7)	0.2	0.2
Income (loss) before income taxes	410.1	440.5	1,290.5	1,181.6
Income tax benefit (expense)	(64.5)	(147.4)	(231.6)	(338.5)
Net Income (loss)	345.6	293.1	1,058.9	843.1
Net (income) loss attributable to noncontrolling interests	(7.3)	(6.1)	(18.4)	(17.7)
Net income (loss) attributable to Molson Coors Brewing Company	$ 338.3	$ 287.0	$ 1,040.5	$ 825.4
Basic net income (loss) attributable to Molson Coors Brewing Company per share:
Income (Loss) from Continuing Operations, Per Basic Share	$ 1.57	$ 1.33	$ 4.82	$ 3.83
Diluted net income (loss) attributable to Molson Coors Brewing Company per share:
Income (Loss) from Continuing Operations, Per Diluted Share	$ 1.56	$ 1.33	$ 4.80	$ 3.81
Weighted average shares - basic (in shares)	216.0	215.5	215.9	215.4
Dilutive effect of share-based awards	0.6	1.0	0.7	1.1
Weighted average shares - diluted (in shares)	216.6	216.5	216.6	216.5
Dividends declared and paid per share (in dollars per share)	$ 0.41	$ 0.41	$ 1.23	$ 1.23
Stock Compensation Plan [Member]
Diluted net income (loss) attributable to Molson Coors Brewing Company per share:
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0.9	0.4	0.9	0.3