Supplemental Equity and Comprehensive Income Information - SE Rf (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Increase (decrease) in equity
Balance at the beginning of the period	$ 13,828	$ 10,214	$ 12,931	$ 10,126
Net income	1,525	1,303	3,152	2,613
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	170	106	(52)	(338)
Defined benefit pension and postretirement plans adjustment	121	47	240	155
Cash flow hedging instruments	(11)	(36)	47	11
Total other comprehensive income (loss), net of tax	280	117	235	(172)
Dividends declared	(858)	(846)	(1,716)	(1,693)
Purchase of subsidiary shares		(1)		(1)
Stock-based compensation	54	50	175	167
Reacquired stock	(499)		(742)	(356)
Issuances pursuant to stock option and benefit plans	186	88	481	241
Balance at the end of the period	14,516	10,925	14,516	10,925
Common Stock and Additional Paid-in Capital
Increase (decrease) in equity
Balance at the beginning of the period	6,292	6,033	6,171	5,916
Other comprehensive income (loss), net of tax:
Stock-based compensation	54	50	175	167
Balance at the end of the period	6,346	6,083	6,346	6,083
Retained Earnings
Increase (decrease) in equity
Balance at the beginning of the period	44,255	42,356	43,821	42,130
Net income	1,524	1,306	3,148	2,614
Other comprehensive income (loss), net of tax:
Dividends declared	(858)	(846)	(1,716)	(1,693)
Issuances pursuant to stock option and benefit plans	(97)	(30)	(429)	(265)
Balance at the end of the period	44,824	42,786	44,824	42,786
Treasury Stock
Increase (decrease) in equity
Balance at the beginning of the period	(29,020)	(29,817)	(29,404)	(29,849)
Other comprehensive income (loss), net of tax:
Reacquired stock	(499)		(742)	(356)
Issuances pursuant to stock option and benefit plans	283	118	910	506
Balance at the end of the period	(29,236)	(29,699)	(29,236)	(29,699)
Total Accumulated Other Comprehensive Income (Loss)
Increase (decrease) in equity
Balance at the beginning of the period	(7,767)	(8,420)	(7,721)	(8,134)
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	171	106	(52)	(335)
Defined benefit pension and postretirement plans adjustment	121	47	240	155
Cash flow hedging instruments	(11)	(36)	47	11
Balance at the end of the period	(7,486)	(8,303)	(7,486)	(8,303)
Noncontrolling Interest
Increase (decrease) in equity
Balance at the beginning of the period	68	62	64	63
Net income	1	(3)	4	(1)
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	(1)			(3)
Purchase of subsidiary shares		(1)		(1)
Balance at the end of the period	$ 68	$ 58	$ 68	$ 58