Supplementary Information Foreign Currency Exchange Gain (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Foreign Currency Exchange Gain (Loss) [Line Items]
Pre-tax exchange (losses) gains - net	$ 1	$ (32)	$ (60)	$ (59)
Foreign Currency Transaction (Loss) Gain Tax (Expense) Benefit	2	18	(15)	12
Foreign Currency Transaction (Loss) Gain After Tax	3	(14)	(75)	(47)
Subsidiary Monetary Position
Foreign Currency Exchange Gain (Loss) [Line Items]
Pre-tax exchange (losses) gains - net	(13)	17	(239)	7
Foreign Currency Transaction (Loss) Gain Tax (Expense) Benefit	5	7	28	(3)
Foreign Currency Transaction (Loss) Gain After Tax	(8)	24	(211)	4
Hedging Program [Member]
Foreign Currency Exchange Gain (Loss) [Line Items]
Pre-tax exchange (losses) gains - net	14	(49)	179	(66)
Foreign Currency Transaction (Loss) Gain Tax (Expense) Benefit	(3)	11	(43)	15
Foreign Currency Transaction (Loss) Gain After Tax	$ 11	$ (38)	$ 136	$ (51)