Hedging Activities (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Derivative Asset, Notional Amount		$ 19,230	$ 16,104
Foreign Exchange Forward [Member] | Not Designated as Hedging Instrument [Member]
Derivative Asset, Notional Amount		6,800	7,700
Foreign Exchange Forward [Member] | Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member]
Derivative Asset, Notional Amount		1,000	2,100
Foreign Exchange Forward [Member] | Cash Flow Hedging [Member] | Not Designated as Hedging Instrument [Member]
Amount reclassified	$ 14
Gross Notional Value, Translated Earnings Contracts [Member]
Derivative Asset, Notional Amount		11,100	12,200
Gross Notional Value, Collar Options [Member]
Derivative Asset, Notional Amount		2,700	2,500
Gross Notional Value, Foreign Exchange Forward [Member]
Derivative Asset, Notional Amount		$ 8,400	$ 9,700