Consolidated Statements of Equity and Redeemable Noncontrolling Interest (Shares of Treasury Stock) - shares shares in Millions	Total	Treasury Stock
Beginning balance at Dec. 31, 2018		(295)
Number of shares repurchased		(14)
Number of shares returned - stock compensation		0
Ending balance at Mar. 31, 2019		(309)
Beginning balance at Dec. 31, 2018		(295)
Number of shares repurchased	(23)
Ending balance at Jun. 30, 2019		(318)
Beginning balance at Mar. 31, 2019		(309)
Number of shares repurchased	(9)	(9)
Number of shares returned - stock compensation		0
Ending balance at Jun. 30, 2019		(318)
Beginning balance at Dec. 31, 2019	(329)	(329)
Number of shares returned - stock compensation		0
Ending balance at Mar. 31, 2020		(329)
Beginning balance at Dec. 31, 2019	(329)	(329)
Number of shares repurchased	0
Ending balance at Jun. 30, 2020	(329)	(329)
Beginning balance at Mar. 31, 2020		(329)
Number of shares repurchased	0
Number of shares returned - stock compensation		0
Ending balance at Jun. 30, 2020	(329)	(329)