Consolidated Statements of Total Equity Consolidated Statements of Total Equity (Parenthetical) - shares	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Beginning Balances, shares		376,261,635
Ending Balances, shares	373,132,964
Common Stock [Member]
Beginning Balances, shares	373,242,060	376,261,635	375,693,966	374,986,079
Exercise of stock options	831,489	806,817	1,046,210	916,913
Stock issued under employee benefit plans	1,059,415	273,608	1,169,341	290,974
Repurchases of common stock	(2,000,000)	(4,100,000)	(500,000)	(500,000)
Ending Balances, shares	373,132,964	373,242,060	377,409,517	375,693,966