Hedging Activities (Narrative) (Details) $ in Millions, ¥ in Billions	Dec. 31, 2019 USD ($)	Dec. 31, 2019 JPY (¥)	Dec. 31, 2018 USD ($)	Jun. 30, 2018 USD ($)
Cash Flow Hedging [Member]
Amount expected to be reclassified into earnings within the next 12 months	$ 30			$ 16
Gross Notional Value, Collar Options [Member] | Not Designated as Hedging Instrument [Member]
Derivative, Notional Amount	2,000
Gross Notional Value Zero-Cost Collars Options [Member] | Not Designated as Hedging Instrument [Member]
Derivative, Notional Amount	7,700
Gross Notional Value Purchased Put Or Call Options [Member] | Not Designated as Hedging Instrument [Member]
Derivative, Notional Amount	2,500
Gross Notional Value, Foreign Exchange Forward [Member] | Cash Flow Hedging [Member]
Derivative, Notional Amount	$ 2,100	¥ 1.5	$ 400