Equity and Accumulated Other Comprehensive Earnings - Equity activity (Details) - USD ($) shares in Thousands, $ in Millions		1 Months Ended		3 Months Ended		6 Months Ended
	Jan. 01, 2019	Jun. 30, 2019	May 31, 2019	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Increase (Decrease) in Stockholders' Equity
Balance at beginning of the period	$ 3,562			$ 3,649	$ 4,138	$ 3,562	$ 4,084
Net earnings				197	120	314	245
Other comprehensive earnings (loss), net of tax				(8)	(94)	117	(111)
Reclassification of stranded tax effects	79
Common dividends, net of tax benefits				(50)	(35)	(84)	(70)
Treasury stock purchases				(251)	(161)	(380)	(202)
Treasury stock purchases (in shares)		(100)	(3,400)
Treasury shares reissued				7	(6)	(12)	11
Shares issued and stock compensation for stock options and other stock plans, net of shares exchanged				18	20	15	36
Other activity				2	1	8	2
Balance at end of the period		$ 3,564		3,564	3,995	3,564	3,995
Common Stock
Increase (Decrease) in Stockholders' Equity
Balance at beginning of the period	$ 1,157			$ 1,154	$ 1,100	$ 1,157	$ 1,084
Balance (in shares)	673,237			674,692	671,611	673,237	670,576
Shares issued and stock compensation for stock options and other stock plans, net of shares exchanged				$ 18	$ 20	$ 15	$ 36
Shares issued and stock compensation for stock options and other stock plans, net of shares exchanged (in shares)				771	459	2,226	1,494
Balance at end of the period		$ 1,172		$ 1,172	$ 1,120	$ 1,172	$ 1,120
Balance (in shares)		675,463		675,463	672,070	675,463	672,070
Treasury Stock, Common
Increase (Decrease) in Stockholders' Equity
Balance at beginning of the period	$ (2,205)			$ (2,323)	$ (1,508)	$ (2,205)	$ (1,474)
Balance (in shares)	337,979			340,223	321,435	337,979	320,695
Treasury stock purchases				$ (251)	$ (161)	$ (380)	$ (202)
Treasury stock purchases (in shares)				(3,540)	(4,219)	(6,174)	(5,259)
Treasury shares reissued				$ 7	$ (6)	$ (12)	$ 11
Treasury shares reissued (in shares)				140	195	530	495
Other activity				$ 1		$ 7	$ 2
Balance at end of the period		$ (2,566)		$ (2,566)	$ (1,663)	$ (2,566)	$ (1,663)
Balance (in shares)		343,623		343,623	325,459	343,623	325,459
Retained Earnings
Increase (Decrease) in Stockholders' Equity
Balance at beginning of the period	$ 5,341			$ 5,504	$ 5,114	$ 5,341	$ 5,024
Net earnings				197	119	314	244
Reclassification of stranded tax effects						79
Common dividends, net of tax benefits				(50)	(35)	(84)	(70)
Other activity					1	1	1
Balance at end of the period		$ 5,651		5,651	5,199	5,651	5,199
Accumulated Other Comprehensive Earnings (Loss)
Increase (Decrease) in Stockholders' Equity
Balance at beginning of the period	(835)			(789)	(673)	(835)	(655)
Other comprehensive earnings (loss), net of tax				(8)	(94)	117	(111)
Reclassification of stranded tax effects						(79)
Other activity							(1)
Balance at end of the period		(797)		(797)	(767)	(797)	(767)
Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity
Balance at beginning of the period	$ 104			103	105	104	105
Net earnings					1		1
Other activity				1
Balance at end of the period		$ 104		$ 104	$ 106	$ 104	$ 106