Acquisition and Investments Transactions with MillerCoors (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Oct. 10, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Millercoors [Member]
Schedule of Equity Method Investments [Line Items]
Beer sales to MillerCoors	$ 7.5		$ 11.7	$ 13.1
Beer purchases from MillerCoors	32.0		43.2	37.3
Service agreement costs and other charges to MillerCoors	1.9		2.6	2.4
Service agreement costs and other charges from MillerCoors	$ 0.9		0.9	1.0
Undistributed Earnings, Basic		$ 0.0	0.0
BRI [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Administrative Fees Related to Agreements		85.8	88.8	103.4
BDL [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Administrative Fees Related to Agreements		$ 34.3	$ 36.4	$ 50.8