Components of Accumulated Other Comprehensive Loss, Net (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance - Accumulated other comprehensive loss, net			$ (1,511)
Other comprehensive income (loss), unrecognized amounts on retirement benefits	$ 15	$ 18	16	$ 80
Other comprehensive income (loss), foreign currency translation adjustment	227	(134)	535	(339)
Other comprehensive income (loss), unrealized gains on available-for-sale securities	423	80	542	151
Other comprehensive income (loss), unrealized gains (losses) on cash flow hedges	1	(3)	(5)	(2)
Other comprehensive income (loss)	666	(39)	1,088	(110)
Ending balance - Accumulated other comprehensive loss, net	(423)		(423)
Accumulated Other Comprehensive (Loss) Income, Net [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance - unrecognized amounts on retirement benefits			(447)	(438)
Beginning balance - foreign currency translation adjustment			(1,675)	(1,092)
Beginning balance - unrealized gains (losses) on available-for-sale securities			585	615
Beginning balance - unrealized gains (losses) on cash flow hedges			26	7
Beginning balance - Accumulated other comprehensive loss, net			(1,511)	(908)
Other comprehensive income (loss), unrecognized amounts on retirement benefits			16	80
Other comprehensive income (loss), foreign currency translation adjustment			535	(339)
Other comprehensive income (loss), unrealized gains on available-for-sale securities			542	151
Other comprehensive income (loss), unrealized gains (losses) on cash flow hedges			(5)	(2)
Other comprehensive income (loss)			1,088	(110)
Ending balance - unrecognized amounts on retirement benefits	(431)	(358)	(431)	(358)
Ending balance - foreign currency translation adjustment	(1,140)	(1,431)	(1,140)	(1,431)
Ending balance - unrealized gains (losses) on available-for-sale securities	1,127	766	1,127	766
Ending balance - unrealized gains (losses) on cash flow hedges	21	5	21	5
Ending balance - Accumulated other comprehensive loss, net	$ (423)	$ (1,018)	$ (423)	$ (1,018)