Hedging Activities (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Derivative Asset, Notional Amount	$ 17,016	$ 14,911
Foreign Exchange Forward [Member] | Not Designated as Hedging Instrument [Member]
Derivative Asset, Notional Amount	8,000	9,100
Foreign Exchange Forward [Member] | Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member]
Derivative Asset, Notional Amount	2,000	400
Derivative, Notional Amount	1,500
Gross Notional Value, Translated Earnings Contracts [Member]
Derivative Asset, Notional Amount	13,200	13,600
Gross Notional Value, Collar Options [Member]
Derivative Asset, Notional Amount	2,500	2,600
Gross Notional Value, Foreign Exchange Forward [Member]
Derivative Asset, Notional Amount	$ 10,700	$ 11,000