Equity Activity - AOCI Rollforward (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Accumulated Other Comprehensive Income (Loss) (net of tax)
Balance at the Beginning of the Period			$ 18,392	$ 14,424
Other comprehensive income/(loss)			1,208	1,002
Balance at the End of the Period	$ 18,544	$ 15,889	18,544	15,889
Accumulated Other Comprehensive Income/(Loss)
Accumulated Other Comprehensive Income (Loss) (net of tax)
Balance at the Beginning of the Period			(29,398)	(29,607)
Other comprehensive income before reclassifications			486	135
Amount reclassified from accumulated other comprehensive income			723	867
Other comprehensive income/(loss)	520	394	1,208	1,002
Balance at the End of the Period	(28,189)	(28,604)	(28,189)	(28,604)
Net Unrealized Gains/(Losses) on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) (net of tax)
Balance at the Beginning of the Period			319	100
Other comprehensive income before reclassifications	(71)	13	(96)	(160)
Amount reclassified from accumulated other comprehensive income			(175)	4
Other comprehensive income/(loss)	(183)	76	(271)	(156)
Balance at the End of the Period	47	(56)	47	(56)
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) (net of tax)
Balance at the Beginning of the Period			(3,603)	(3,463)
Other comprehensive income before reclassifications			510	351
Amount reclassified from accumulated other comprehensive income			0	0
Other comprehensive income/(loss)	240	(154)	510	351
Balance at the End of the Period	(3,093)	(3,112)	(3,093)	(3,112)
Net Change Retirement-Related Benefit Plans
Accumulated Other Comprehensive Income (Loss) (net of tax)
Balance at the Beginning of the Period			(26,116)	(26,248)
Other comprehensive income before reclassifications			70	(34)
Amount reclassified from accumulated other comprehensive income			897	840
Other comprehensive income/(loss)	461	471	967	806
Balance at the End of the Period	(25,148)	(25,442)	(25,148)	(25,442)
Net Unrealized Gains/(Losses) on Available-For-Sale Securities
Accumulated Other Comprehensive Income (Loss) (net of tax)
Balance at the Beginning of the Period			2	5
Other comprehensive income before reclassifications	2	1	2	(22)
Amount reclassified from accumulated other comprehensive income			1	23
Other comprehensive income/(loss)	2	1	2	1
Balance at the End of the Period	$ 5	$ 6	$ 5	$ 6