Background and Basis of Presentation (Narrative) (Details) - USD ($) $ / shares in Units, shares in Millions	3 Months Ended		15 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Sep. 30, 2015	Dec. 31, 2015	Jul. 31, 2015	Jul. 31, 2014
Equity, Class of Treasury Stock [Line Items]
Repurchase of common stock, shares	2.8	3.6
Average price of repurchased shares, per share	$ 59.81	$ 53.03
Accounting Standards Update 2015-03 [Member]
Equity, Class of Treasury Stock [Line Items]
Debt issuance costs	$ 70,000,000			$ 72,000,000
July 2014 Share Repurchase Program [Member]
Equity, Class of Treasury Stock [Line Items]
Planned share repurchase program						$ 1,000,000,000
Repurchase of common stock, shares			20.4
Average price of repurchased shares, per share			$ 48.90
July 2015 Share Repurchase Program [Member]
Equity, Class of Treasury Stock [Line Items]
Planned share repurchase program					$ 1,000,000,000.0
Remaining authorized repurchase amount	$ 797,000,000
SABMiller Plc [Member]
Equity, Class of Treasury Stock [Line Items]
Equity method investment, ownership percentage (approximately)	27.00%