Sales Of Receivables (Summary of Receivables Sold) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Receivables [Abstract]
Gross receivables sold/cash proceeds received	$ 3,563,000,000	$ 2,873,000,000	$ 11,590,000,000	$ 8,725,000,000
Collections reinvested under revolving agreement	3,563,000,000	2,873,000,000	10,590,000,000	5,000,000,000
Collections not reinvested	200,000,000	269,000,000	200,000,000	269,000,000
Net cash proceeds received (remitted)	(200,000,000)	(269,000,000)	800,000,000	3,456,000,000
Net receivables sold	3,553,000,000	2,864,000,000	11,510,000,000	8,361,000,000
Obligations recorded (reversed)	58,000,000	39,000,000	172,000,000	475,000,000
Initial sale of receivables	$ 0	$ 0	$ 1,000,000,000	$ 3,725,000,000