Debt (Details) - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Total short-term debt	$ 18,811,000,000	$ 19,624,000,000
Unamortized discount	13,000,000	23,000,000
Unamortized debt issuance costs	(233,000,000)	(197,000,000)
Fair value adjustments	(1,865,000,000)	(1,690,000,000)
Total long-term debt	104,081,000,000	99,415,000,000
Total debt	$ 122,892,000,000	$ 119,039,000,000
Average Contractual (interest rate)	4.50%	3.60%
Average Effective (interest rate)	4.50%	3.60%
Debt Carrying Value Fair Value	$ 37,300,000,000	$ 33,300,000,000
Fair value of short-term debt	15,700,000,000	16,900,000,000
Discontinued Hedged Debt	(320,000,000)	31,000,000
Floating Rate Demand Notes [Member]
Debt Instrument [Line Items]
Total short-term debt	10,782,000,000	10,303,000,000
Other short-term debt [Member]
Debt Instrument [Line Items]
Total short-term debt	4,897,000,000	6,515,000,000
Asset-backed Securities [Member]
Debt Instrument [Line Items]
Total short-term debt	3,132,000,000	2,806,000,000
Unsecured Debt [Member]
Debt Instrument [Line Items]
Notes payable within one year	10,664,000,000	7,980,000,000
Notes payable after one year	42,700,000,000	39,620,000,000
Asset-backed Securities [Member]
Debt Instrument [Line Items]
Notes payable within one year	18,756,000,000	21,839,000,000
Notes payable after one year	$ 34,046,000,000	$ 31,840,000,000
Total short-term debt [Member]
Debt Instrument [Line Items]
Average Contractual (interest rate)	5.00%	3.80%
Average Effective (interest rate)	5.00%	3.80%
Total long-term debt [Member]
Debt Instrument [Line Items]
Average Contractual (interest rate)	4.50%	3.60%
Average Effective (interest rate)	4.50%	3.60%
Fair Value, Nonrecurring [Member] | Level 2 [Member]
Debt Instrument [Line Items]
Fair value of debt	$ 122,386,000,000	$ 117,214,000,000