Hedging Activities (Effect on Consolidated Financial Statements) (Details) - Not Designated as Hedging Instrument [Member] - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Gains recognized in income	$ 269	$ (71)	$ (137)
Foreign Exchange And Other Contracts - Balance Sheet, Loans And Other [Member] \| Other Income, Net [Member]
Gains recognized in income	21	22	(16)
Foreign Currency Hedges Related To Translated Earnings [Member] \| Translated Earnings Contract Gain, Net [Member]
Gains recognized in income	$ 248	$ (93)	$ (121)

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4A
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5618551-113959

Name:	us-gaap_DerivativeGainLossOnDerivativeNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration