Supplemental Guarantor Information - Balance Sheet (Details) - USD ($) $ in Millions	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 731.3		$ 523.4	$ 410.2		$ 1,057.9
Accounts receivable, net	694.2		714.8
Other receivables, net	123.1		105.5
Inventories, net	657.7		615.9
Other current assets, net	434.2		224.8
Intercompany accounts receivable	0.0		0.0
Total current assets	2,640.5		2,184.4
Properties, net	4,180.1		4,546.5
Goodwill	7,624.1		7,631.4
Other intangibles, net	13,410.4		13,656.0
Net investment in and advances to subsidiaries	0.0		0.0
Other assets	820.2		841.5
Total assets	28,675.3		28,859.8
Current liabilities:
Accounts payable and other current liabilities	3,068.4		2,767.3
Current portion of long-term debt and short-term borrowings	1,242.1		928.2
Intercompany accounts payable	0.0		0.0
Total current liabilities	4,310.5		3,695.5
Long-term debt	7,129.5		8,109.5
Pension and postretirement benefits	691.5		716.6
Deferred tax liabilities	2,276.0		2,258.6
Other liabilities	492.2		406.5
Intercompany notes payable	0.0		0.0
Total liabilities	14,899.7		15,186.7
MCBC stockholders' equity	13,512.7		13,419.4
Intercompany notes receivable	0.0		0.0
Total Molson Coors Beverage Company stockholders' equity	13,512.7		13,419.4
Noncontrolling interests	262.9		253.7
Total equity	13,775.6	$ 13,268.0	13,673.1	13,406.5	$ 14,145.0	13,735.8
Total liabilities and equity	28,675.3		28,859.8
Eliminations
Current assets:
Cash and cash equivalents	0.0		0.0	0.0		0.0
Accounts receivable, net	0.0		0.0
Other receivables, net	0.0		0.0
Inventories, net	0.0		0.0
Other current assets, net	0.0		0.0
Intercompany accounts receivable	(2,038.7)		(299.0)
Total current assets	(2,038.7)		(299.0)
Properties, net	0.0		0.0
Goodwill	0.0		0.0
Other intangibles, net	0.0		0.0
Net investment in and advances to subsidiaries	(34,429.3)		(34,063.4)
Other assets	(82.4)		(78.0)
Total assets	(36,550.4)		(34,440.4)
Current liabilities:
Accounts payable and other current liabilities	0.0		0.0
Current portion of long-term debt and short-term borrowings	0.0		0.0
Intercompany accounts payable	(2,038.7)		(299.0)
Total current liabilities	(2,038.7)		(299.0)
Long-term debt	0.0		0.0
Pension and postretirement benefits	0.0		0.0
Deferred tax liabilities	(82.4)		(78.0)
Other liabilities	0.0		0.0
Intercompany notes payable	(7,730.8)		(65.0)
Total liabilities	(9,851.9)		(442.0)
MCBC stockholders' equity	(34,429.3)		(34,063.4)
Intercompany notes receivable	7,730.8		65.0
Total Molson Coors Beverage Company stockholders' equity	(26,698.5)		(33,998.4)
Noncontrolling interests	0.0		0.0
Total equity	(26,698.5)		(33,998.4)
Total liabilities and equity	(36,550.4)		(34,440.4)
Parent Issuer
Current assets:
Cash and cash equivalents	48.4		15.7	14.6		515.8
Accounts receivable, net	0.0		0.0
Other receivables, net	2.4		14.4
Inventories, net	0.0		0.0
Other current assets, net	0.8		3.0
Intercompany accounts receivable	458.2		94.1
Total current assets	509.8		127.2
Properties, net	3.0		19.8
Goodwill	0.0		0.0
Other intangibles, net	2.5		4.0
Net investment in and advances to subsidiaries	22,014.5		21,200.6
Other assets	122.0		137.2
Total assets	22,651.8		21,488.8
Current liabilities:
Accounts payable and other current liabilities	167.2		170.7
Current portion of long-term debt and short-term borrowings	1,224.0		499.7
Intercompany accounts payable	1,208.0		0.0
Total current liabilities	2,599.2		670.4
Long-term debt	6,293.7		7,250.3
Pension and postretirement benefits	7.7		7.2
Deferred tax liabilities	0.0		0.0
Other liabilities	239.7		142.6
Intercompany notes payable	0.0		0.0
Total liabilities	9,140.3		8,070.5
MCBC stockholders' equity	13,512.7		13,419.4
Intercompany notes receivable	(1.2)		(1.1)
Total Molson Coors Beverage Company stockholders' equity	13,511.5		13,418.3
Noncontrolling interests	0.0		0.0
Total equity	13,511.5		13,418.3
Total liabilities and equity	22,651.8		21,488.8
Subsidiary Guarantors
Current assets:
Cash and cash equivalents	152.5		119.6	79.8		156.1
Accounts receivable, net	375.5		396.3
Other receivables, net	77.2		58.4
Inventories, net	494.5		449.1
Other current assets, net	313.7		126.0
Intercompany accounts receivable	1,487.7		190.0
Total current assets	2,901.1		1,339.4
Properties, net	3,013.8		3,294.7
Goodwill	6,141.1		6,146.5
Other intangibles, net	11,530.5		11,750.6
Net investment in and advances to subsidiaries	8,152.1		8,364.9
Other assets	361.2		364.4
Total assets	32,099.8		31,260.5
Current liabilities:
Accounts payable and other current liabilities	1,830.3		1,722.0
Current portion of long-term debt and short-term borrowings	5.7		415.1
Intercompany accounts payable	496.0		150.7
Total current liabilities	2,332.0		2,287.8
Long-term debt	760.5		779.1
Pension and postretirement benefits	669.9		695.5
Deferred tax liabilities	1,608.2		1,593.3
Other liabilities	164.0		172.2
Intercompany notes payable	3,942.2		0.0
Total liabilities	9,476.8		5,527.9
MCBC stockholders' equity	26,410.4		25,796.5
Intercompany notes receivable	(3,787.4)		(63.9)
Total Molson Coors Beverage Company stockholders' equity	22,623.0		25,732.6
Noncontrolling interests	0.0		0.0
Total equity	22,623.0		25,732.6
Total liabilities and equity	32,099.8		31,260.5
Subsidiary Non Guarantors
Current assets:
Cash and cash equivalents	530.4		388.1	$ 315.8		$ 386.0
Accounts receivable, net	318.7		318.5
Other receivables, net	43.5		32.7
Inventories, net	163.2		166.8
Other current assets, net	119.7		95.8
Intercompany accounts receivable	92.8		14.9
Total current assets	1,268.3		1,016.8
Properties, net	1,163.3		1,232.0
Goodwill	1,483.0		1,484.9
Other intangibles, net	1,877.4		1,901.4
Net investment in and advances to subsidiaries	4,262.7		4,497.9
Other assets	419.4		417.9
Total assets	10,474.1		10,550.9
Current liabilities:
Accounts payable and other current liabilities	1,070.9		874.6
Current portion of long-term debt and short-term borrowings	12.4		13.4
Intercompany accounts payable	334.7		148.3
Total current liabilities	1,418.0		1,036.3
Long-term debt	75.3		80.1
Pension and postretirement benefits	13.9		13.9
Deferred tax liabilities	750.2		743.3
Other liabilities	88.5		91.7
Intercompany notes payable	3,788.6		65.0
Total liabilities	6,134.5		2,030.3
MCBC stockholders' equity	8,018.9		8,266.9
Intercompany notes receivable	(3,942.2)		0.0
Total Molson Coors Beverage Company stockholders' equity	4,076.7		8,266.9
Noncontrolling interests	262.9		253.7
Total equity	4,339.6		8,520.6
Total liabilities and equity	$ 10,474.1		$ 10,550.9