Supplemental Guarantor Information - Income Statement (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Condensed Consolidating Statement of Operations
Sales	$ 3,378.4	$ 3,498.0	$ 8,946.0	$ 9,918.1
Excise taxes	(624.9)	(656.4)	(1,586.3)	(1,824.9)
Net sales	2,753.5	2,841.6	7,359.7	8,093.2
Cost of goods sold	(1,551.0)	(1,685.4)	(4,486.6)	(4,858.2)
Gross profit	1,202.5	1,156.2	2,873.1	3,235.0
Marketing, general and administrative expenses	(634.5)	(690.2)	(1,788.7)	(2,115.1)
Special items, net	(59.7)	(703.3)	(210.6)	(666.4)
Equity income (loss) in subsidiaries	0.0	0.0	0.0	0.0
Operating income (loss)	508.3	(237.3)	873.8	453.5
Interest income (expense), net	(67.9)	(65.6)	(206.5)	(204.5)
Other pension and postretirement benefits (costs), net	7.6	8.0	22.7	25.0
Other income (expense), net	2.4	(13.7)	3.4	(0.7)
Income (loss) before income taxes	450.4	(308.6)	693.4	273.3
Income tax benefit (expense)	(104.0)	(90.7)	(265.2)	(193.3)
Net income (loss) including noncontrolling interests	346.4	(399.3)	428.2	80.0
Net (income) loss attributable to noncontrolling interests	(3.6)	(3.5)	(7.4)	(2.0)
Net income (loss) attributable to MCBC	342.8	(402.8)	420.8	78.0
Comprehensive income (loss) attributable to MCBC	505.0	(602.5)	199.6	(75.5)
Parent Issuer
Condensed Consolidating Statement of Operations
Sales	4.4	31.5	10.1	96.1
Excise taxes	0.0	0.0	0.0	0.0
Net sales	4.4	31.5	10.1	96.1
Cost of goods sold	(0.5)	(2.0)	(1.4)	(5.9)
Gross profit	3.9	29.5	8.7	90.2
Marketing, general and administrative expenses	(22.2)	(45.0)	(85.3)	(188.1)
Special items, net	(1.4)	0.0	(16.8)	(0.4)
Equity income (loss) in subsidiaries	400.2	(398.3)	641.3	221.5
Operating income (loss)	380.5	(413.8)	547.9	123.2
Interest income (expense), net	(59.3)	(74.7)	(179.7)	(228.3)
Other pension and postretirement benefits (costs), net	(0.1)	0.0	(0.4)	0.0
Other income (expense), net	0.6	(0.4)	0.3	(0.5)
Income (loss) before income taxes	321.7	(488.9)	368.1	(105.6)
Income tax benefit (expense)	21.1	86.1	52.7	183.6
Net income (loss) including noncontrolling interests	342.8	(402.8)	420.8	78.0
Net (income) loss attributable to noncontrolling interests	0.0	0.0	0.0	0.0
Net income (loss) attributable to MCBC	342.8	(402.8)	420.8	78.0
Comprehensive income (loss) attributable to MCBC	505.0	(602.5)	199.6	(75.5)
Subsidiary Guarantors
Condensed Consolidating Statement of Operations
Sales	2,588.2	2,631.6	7,156.6	7,606.7
Excise taxes	(354.1)	(367.6)	(964.1)	(1,032.5)
Net sales	2,234.1	2,264.0	6,192.5	6,574.2
Cost of goods sold	(1,241.4)	(1,330.5)	(3,696.9)	(3,864.2)
Gross profit	992.7	933.5	2,495.6	2,710.0
Marketing, general and administrative expenses	(479.2)	(528.6)	(1,304.5)	(1,552.1)
Special items, net	(27.8)	(324.9)	(154.9)	(281.3)
Equity income (loss) in subsidiaries	(6.7)	(320.3)	(240.0)	(450.0)
Operating income (loss)	479.0	(240.3)	796.2	426.6
Interest income (expense), net	23.2	87.2	38.1	255.7
Other pension and postretirement benefits (costs), net	5.1	1.2	15.3	3.5
Other income (expense), net	1.9	(59.7)	1.8	(67.1)
Income (loss) before income taxes	509.2	(211.6)	851.4	618.7
Income tax benefit (expense)	(109.1)	(185.4)	(208.8)	(395.2)
Net income (loss) including noncontrolling interests	400.1	(397.0)	642.6	223.5
Net (income) loss attributable to noncontrolling interests	0.0	0.0	0.0	0.0
Net income (loss) attributable to MCBC	400.1	(397.0)	642.6	223.5
Comprehensive income (loss) attributable to MCBC	581.2	(592.5)	583.0	102.3
Subsidiary Non Guarantors
Condensed Consolidating Statement of Operations
Sales	929.3	1,004.3	2,174.3	2,688.1
Excise taxes	(270.8)	(288.8)	(622.2)	(792.4)
Net sales	658.5	715.5	1,552.1	1,895.7
Cost of goods sold	(446.1)	(477.5)	(1,165.4)	(1,323.0)
Gross profit	212.4	238.0	386.7	572.7
Marketing, general and administrative expenses	(139.6)	(161.4)	(416.8)	(512.8)
Special items, net	(30.5)	(378.4)	(38.9)	(384.7)
Equity income (loss) in subsidiaries	52.3	(265.3)	48.6	(186.2)
Operating income (loss)	94.6	(567.1)	(20.4)	(511.0)
Interest income (expense), net	(31.8)	(78.1)	(64.9)	(231.9)
Other pension and postretirement benefits (costs), net	2.6	6.8	7.8	21.5
Other income (expense), net	(0.1)	46.4	1.3	66.9
Income (loss) before income taxes	65.3	(592.0)	(76.2)	(654.5)
Income tax benefit (expense)	(16.0)	8.6	(109.1)	18.3
Net income (loss) including noncontrolling interests	49.3	(583.4)	(185.3)	(636.2)
Net (income) loss attributable to noncontrolling interests	(3.6)	(3.5)	(7.4)	(2.0)
Net income (loss) attributable to MCBC	45.7	(586.9)	(192.7)	(638.2)
Comprehensive income (loss) attributable to MCBC	252.9	(696.9)	(270.3)	(760.2)
Eliminations
Condensed Consolidating Statement of Operations
Sales	(143.5)	(169.4)	(395.0)	(472.8)
Excise taxes	0.0	0.0	0.0	0.0
Net sales	(143.5)	(169.4)	(395.0)	(472.8)
Cost of goods sold	137.0	124.6	377.1	334.9
Gross profit	(6.5)	(44.8)	(17.9)	(137.9)
Marketing, general and administrative expenses	6.5	44.8	17.9	137.9
Special items, net	0.0	0.0	0.0	0.0
Equity income (loss) in subsidiaries	(445.8)	983.9	(449.9)	414.7
Operating income (loss)	(445.8)	983.9	(449.9)	414.7
Interest income (expense), net	0.0	0.0	0.0	0.0
Other pension and postretirement benefits (costs), net	0.0	0.0	0.0	0.0
Other income (expense), net	0.0	0.0	0.0	0.0
Income (loss) before income taxes	(445.8)	983.9	(449.9)	414.7
Income tax benefit (expense)	0.0	0.0	0.0	0.0
Net income (loss) including noncontrolling interests	(445.8)	983.9	(449.9)	414.7
Net (income) loss attributable to noncontrolling interests	0.0	0.0	0.0	0.0
Net income (loss) attributable to MCBC	(445.8)	983.9	(449.9)	414.7
Comprehensive income (loss) attributable to MCBC	$ (834.1)	$ 1,289.4	$ (312.7)	$ 657.9