Equity Activity - AOCI Rollforward (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss) (net of tax)
Balance at the Beginning of the Period	$ 20,128	$ 16,607	$ 20,985	$ 16,929
Other comprehensive income/(loss)	527	340	(160)	649
Balance at the End of the Period	20,688	17,776	20,688	17,776
Accumulated Other Comprehensive Income/(Loss)
Accumulated Other Comprehensive Income (Loss) (net of tax)
Balance at the Beginning of the Period	(29,283)	(29,182)	(28,597)	(29,490)
Other comprehensive income before reclassifications			(1,025)	29
Amount reclassified from accumulated other comprehensive income			866	620
Other comprehensive income/(loss)	527	340	(160)	649
Balance at the End of the Period	(28,757)	(28,841)	(28,757)	(28,841)
Net Unrealized Gains/(Losses) on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) (net of tax)
Balance at the Beginning of the Period			(179)	284
Other comprehensive income before reclassifications	(26)	(4)	(162)	(272)
Amount reclassified from accumulated other comprehensive income			25	(51)
Other comprehensive income/(loss)	(70)	(129)	(137)	(323)
Balance at the End of the Period	(316)	(39)	(316)	(39)
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) (net of tax)
Balance at the Beginning of the Period			(3,700)	(3,690)
Other comprehensive income before reclassifications			(902)	214
Other comprehensive income/(loss)	139	42	(902)	214
Balance at the End of the Period	(4,602)	(3,477)	(4,602)	(3,477)
Net Change Retirement-Related Benefit Plans
Accumulated Other Comprehensive Income (Loss) (net of tax)
Balance at the Beginning of the Period			(24,718)	(26,083)
Other comprehensive income before reclassifications			38	89
Amount reclassified from accumulated other comprehensive income			841	671
Other comprehensive income/(loss)	457	430	879	760
Balance at the End of the Period	(23,839)	(25,323)	(23,839)	(25,323)
Net Unrealized Gains/(Losses) on Available-For-Sale Securities
Accumulated Other Comprehensive Income (Loss) (net of tax)
Balance at the Beginning of the Period			0	0
Other comprehensive income before reclassifications	1	(1)	1	(2)
Other comprehensive income/(loss)	1	(1)	1	(2)
Balance at the End of the Period	$ 1	$ (2)	$ 1	$ (2)