CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income (loss) including noncontrolling interests	$ (945.7)	$ 246.2	$ 1,134.6
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	113.6	177.6	(359.0)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax	0.0	0.0	6.0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax	(85.7)	(84.2)	10.9
Reclassification of derivative (gain) loss to income	(0.4)	0.5	2.5
Pension and other postretirement benefit adjustments	(39.9)	(39.8)	43.5
Amortization of net prior service (benefit) cost and net actuarial (gain) loss to income and settlement	(5.2)	19.7	4.9
Ownership share of unconsolidated subsidiaries' other comprehensive income (loss)	14.2	(10.6)	(0.8)
Total other comprehensive income (loss), net of tax	(3.4)	63.2	(292.0)
Comprehensive income (loss)	(949.1)	309.4	842.6
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	(5.5)	(5.1)	(16.1)
Comprehensive income (loss) attributable to Molson Coors Beverage Company	$ (954.6)	$ 304.3	$ 826.5