Background and Basis of Presentation (Narrative) (Details) - USD ($) $ / shares in Units, shares in Millions		1 Months Ended	3 Months Ended			9 Months Ended		12 Months Ended	31 Months Ended
	Dec. 31, 2017	Jan. 31, 2018	Sep. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Jan. 31, 2018	Oct. 25, 2018	May 31, 2018	Jul. 31, 2017	Dec. 31, 2016	Oct. 31, 2016	Jul. 31, 2015
Equity, Class of Treasury Stock [Line Items]
Common stock, increase (decrease) in dividend rate, percentage			14.30%	6.10%		21.20%
Dividends declared (usd per share)	$ 0.66		$ 0.8	$ 0.7		$ 2.20	$ 1.88	$ 2.54
Annualized dividend rate (usd per share)						$ 3.20
Repurchase of common stock (shares)			6.2		11.1	21.8	33.2
Aggregate cost of shares repurchased			$ 367,000,000		$ 759,000,000	$ 1,317,000,000	$ 2,359,000,000	$ 2,917,000,000
Average price of repurchased shares, per share (usd per share)			$ 59.18		$ 67.99	$ 60.53	$ 70.97
Net periodic benefit income, excluding service cost			$ 21,000,000		$ 18,000,000	$ 37,000,000	$ 37,000,000
AB InBev [Member]
Equity, Class of Treasury Stock [Line Items]
Fair value of equity investment	$ 22,100,000,000		$ 17,200,000,000			$ 17,200,000,000		22,100,000,000
Equity method investment, ownership percentage (approximately)			10.10%			10.10%
July 2015 Share Repurchase Program [Member]
Equity, Class of Treasury Stock [Line Items]
Planned share repurchase program												$ 4,000,000,000		$ 3,000,000,000	$ 1,000,000,000
Repurchase of common stock (shares)		0.3							58.7
Average price of repurchased shares, per share (usd per share)		$ 71.68							$ 68.15
January 2018 Share Repurchase Program [Member]
Equity, Class of Treasury Stock [Line Items]
Planned share repurchase program		$ 1,000,000,000							$ 1,000,000,000		$ 2,000,000,000
Repurchase of common stock (shares)			6.2			21.5
Aggregate cost of shares repurchased			$ 367,000,000			$ 1,299,000,000
Average price of repurchased shares, per share (usd per share)			$ 59.18			$ 60.40
Stock repurchase program, remaining authorized repurchase amount			$ 700,000,000			$ 700,000,000
Accounting Standards Update 2016-18 [Member]
Equity, Class of Treasury Stock [Line Items]
Restricted cash	$ 61,000,000		$ 99,000,000		61,000,000	$ 99,000,000	61,000,000	$ 61,000,000					$ 82,000,000
Cost of Sales [Member] | Account Standards Update 2017-07 [Member]
Equity, Class of Treasury Stock [Line Items]
Net periodic benefit income, excluding service cost					12,000,000		20,000,000
Marketing, Adminstration and Research Costs [Member] | Account Standards Update 2017-07 [Member]
Equity, Class of Treasury Stock [Line Items]
Net periodic benefit income, excluding service cost					$ 6,000,000		$ 17,000,000
Subsequent Event [Member] | AB InBev [Member]
Equity, Class of Treasury Stock [Line Items]
Fair value of equity investment										$ 14,500,000,000