Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Other comprehensive income from continuing operations, net of income taxes
Beginning of Period	$ 20,538
Other comprehensive income (loss)	582	$ (193)
End of Period	31,362
Cumulative Foreign Currency Translation Adjustments
Other comprehensive income from continuing operations, net of income taxes
Beginning of Period	(4,959)	(4,829)
Impact of business dispositions	142
Other comprehensive (loss) income before reclassifications	533	421
Other comprehensive income (loss)	533	421
End of Period	(4,284)	(4,408)
Net Actuarial Losses and Prior Service Costs and Credits
Other comprehensive income from continuing operations, net of income taxes
Beginning of Period	(2,284)	(1,958)
Impact of business dispositions	6
Amounts reclassified from accumulated other comprehensive income	34	18
Other comprehensive income (loss)	34	18
End of Period	(2,244)	(1,940)
Cumulative Unrealized Gains (Losses) on Marketable Equity Securities
Other comprehensive income from continuing operations, net of income taxes
Beginning of Period	(69)	65
Other comprehensive (loss) income before reclassifications	181	(543)
Amounts reclassified from accumulated other comprehensive income	(101)
Other comprehensive income (loss)	80	(543)
End of Period	11	(478)
Cumulative Gains (Losses) on Derivative Instruments Designated as Cash Flow Hedges
Other comprehensive income from continuing operations, net of income taxes
Beginning of Period	49	64
Impact of business dispositions	1
Other comprehensive (loss) income before reclassifications	(69)	(58)
Amounts reclassified from accumulated other comprehensive income	4	(31)
Other comprehensive income (loss)	(65)	(89)
End of Period	$ (15)	$ (25)