Quarterly Financial Information (Unaudited) Quarterly Financial Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Sales	$ 3,091.0	$ 3,498.0	$ 3,620.0	$ 2,800.1	$ 3,024.4	$ 3,625.1	$ 3,820.5	$ 2,868.0	$ 13,009.1	$ 13,338.0	$ 13,471.5
Excise taxes	(604.8)	(656.4)	(671.7)	(496.8)	(605.7)	(690.9)	(735.3)	(536.5)	(2,429.7)	(2,568.4)	(2,468.7)
Net Sales	2,486.2	2,841.6	2,948.3	2,303.3	2,418.7	2,934.2	3,085.2	2,331.5	10,579.4	10,769.6	11,002.8
Cost of Goods Sold	(1,520.0)	(1,685.4)	(1,759.8)	(1,413.0)	(1,596.0)	(1,714.0)	(1,739.1)	(1,535.7)	(6,378.2)	(6,584.8)	(6,236.7)
Gross profit	966.2	1,156.2	1,188.5	890.3	822.7	1,220.2	1,346.1	795.8	4,201.2	4,184.8	4,766.1
Amounts attributable to MCBC
Net income (loss) attributable to Molson Coors Beverage Company	$ 163.7	$ (402.8)	$ 329.4	$ 151.4	$ 76.0	$ 338.3	$ 424.1	$ 278.1	$ 241.7	$ 1,116.5	$ 1,565.6
Basic net income (loss) attributable to Molson Coors Beverage Company per share (in dollars per share)	$ 0.76	$ (1.86)	$ 1.52	$ 0.70	$ 0.35	$ 1.57	$ 1.96	$ 1.29	$ 1.12	$ 5.17	$ 7.27
Basic net income (loss) attributable to Molson Coors Beverage Company per share
Diluted net income (loss) attributable to Molson Coors Beverage Company per share (in dollars per share)	$ 0.75	$ (1.86)	$ 1.52	$ 0.70	$ 0.35	$ 1.56	$ 1.96	$ 1.28	$ 1.11	$ 5.15	$ 7.23