Provision for Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Income Taxes Information [Line Items]
Net exchange (loss) gain associated with hedging program	$ (304)	$ 434
Tax credit carryforward/back, net	516
Tax effect of net carryforwards/backs, net of valuation allowances, not subject to expiration	285
Unremitted earnings of subsidiaries outside the U.S.	17,380
Expires After 2016 but before 2021 [Member]
Income Taxes Information [Line Items]
Tax credit carryforward/back, net	$ 3
Expiration date of net carryforwards/backs	before the end of 2021
Expires After 2021 [Member]
Income Taxes Information [Line Items]
Tax credit carryforward/back, net	$ 228
Expiration date of net carryforwards/backs	after 2021
Minimum [Member]
Income Taxes Information [Line Items]
Minimum amount of net reductions to company's global unrecognized tax benefit	$ 70
Maximum [Member]
Income Taxes Information [Line Items]
Minimum amount of net reductions to company's global unrecognized tax benefit	$ 90