Supplemental Equity and Comprehensive Income Information - SE Rf (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Increase (decrease) in equity
Balance at the beginning of the period	$ 10,209	$ 9,757	$ 10,126	$ 9,848
Net income	1,287	1,131	2,581	2,024
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	106	123	(338)	200
Defined benefit pension and postretirement plans adjustment	58	196	177	280
Cash flow hedging instruments	(36)	(38)	11	(32)
Total other comprehensive income (loss), net of tax	128	281	(150)	448
Dividends declared	(846)	(830)	(1,693)	(1,660)
Purchase of subsidiary shares	(1)		(1)
Stock-based compensation	50	57	167	169
Reacquired stock		(404)	(356)	(1,070)
Issuances pursuant to stock option and benefit plans	88	150	241	369
Balance at the end of the period	10,915	10,142	10,915	10,142
ASU 2016-02 Leases
Increase (decrease) in equity
Impact of ASUs		14		14
Common Stock and Additional Paid-in Capital
Increase (decrease) in equity
Balance at the beginning of the period	6,033	5,764	5,916	5,652
Other comprehensive income (loss), net of tax:
Stock-based compensation	50	57	167	169
Balance at the end of the period	6,083	5,821	6,083	5,821
Retained Earnings
Increase (decrease) in equity
Balance at the beginning of the period	42,345	41,159	42,135	40,636
Net income	1,290	1,127	2,582	2,018
Other comprehensive income (loss), net of tax:
Dividends declared	(846)	(830)	(1,693)	(1,660)
Issuances pursuant to stock option and benefit plans	(30)	(94)	(265)	(499)
Balance at the end of the period	42,759	41,362	42,759	41,362
Retained Earnings | ASU 2018-02 Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income
Increase (decrease) in equity
Impact of ASUs		853		853
Retained Earnings | ASU 2016-02 Leases
Increase (decrease) in equity
Impact of ASUs		14		14
Treasury Stock
Increase (decrease) in equity
Balance at the beginning of the period	(29,817)	(29,668)	(29,849)	(29,626)
Other comprehensive income (loss), net of tax:
Reacquired stock		(404)	(356)	(1,070)
Issuances pursuant to stock option and benefit plans	118	244	506	868
Balance at the end of the period	(29,699)	(29,828)	(29,699)	(29,828)
Total Accumulated Other Comprehensive Income (Loss)
Increase (decrease) in equity
Balance at the beginning of the period	(8,414)	(7,552)	(8,139)	(6,866)
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	106	122	(335)	199
Defined benefit pension and postretirement plans adjustment	58	196	177	280
Cash flow hedging instruments	(36)	(38)	11	(32)
Balance at the end of the period	(8,286)	(7,272)	(8,286)	(7,272)
Total Accumulated Other Comprehensive Income (Loss) | ASU 2018-02 Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income
Increase (decrease) in equity
Impact of ASUs		(853)		(853)
Noncontrolling Interest
Increase (decrease) in equity
Balance at the beginning of the period	62	54	63	52
Net income	(3)	4	(1)	6
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment		1	(3)	1
Purchase of subsidiary shares	(1)		(1)
Balance at the end of the period	$ 58	$ 59	$ 58	$ 59