Fair Values (Details 2) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Card Member Receivables
Fair Values (Textuals)
Financing receivables, gross	$ 58,221	$ 57,613
Card Member Loans
Fair Values (Textuals)
Financing receivables, gross	114,602	107,964
Variable Interest Entity, Primary Beneficiary | Card Member Receivables
Fair Values (Textuals)
Financing receivables, gross	5,049	5,193
Variable Interest Entity, Primary Beneficiary | Card Member Loans
Fair Values (Textuals)
Financing receivables, gross	27,400	28,461
Carrying Value
Financial assets for which carrying values equal or approximate fair value
Cash and cash equivalents	43,000	34,000
Other financial assets	61,000	60,000
Financial assets carried at other than fair value
Card Member and Other loans, less reserves	116,000	110,000
Financial Liabilities:
Financial liabilities for which carrying values equal or approximate fair value	129,000	123,000
Financial liabilities carried at other than fair value
Certificates of deposit	20,000	16,000
Long-term debt	47,000	43,000
Fair Values (Textuals)
Long-term debt	47,000	43,000
Corresponding Fair Value Amount
Financial assets for which carrying values equal or approximate fair value
Cash and cash equivalents	43,000	34,000
Other financial assets	61,000	60,000
Financial Liabilities:
Financial liabilities for which carrying values equal or approximate fair value	129,000	123,000
Corresponding Fair Value Amount | Variable Interest Entity, Primary Beneficiary | Card Member Receivables
Fair Values (Textuals)
Financing receivables, gross	5,000	5,200
Corresponding Fair Value Amount | Level 1
Financial assets for which carrying values equal or approximate fair value
Cash and cash equivalents	41,000	32,000
Other financial assets	0	0
Financial Liabilities:
Financial liabilities for which carrying values equal or approximate fair value	0	0
Corresponding Fair Value Amount | Level 2
Financial assets for which carrying values equal or approximate fair value
Cash and cash equivalents	2,000	2,000
Other financial assets	61,000	60,000
Financial Liabilities:
Financial liabilities for which carrying values equal or approximate fair value	129,000	123,000
Corresponding Fair Value Amount | Level 3
Financial assets for which carrying values equal or approximate fair value
Cash and cash equivalents	0	0
Other financial assets	0	0
Financial Liabilities:
Financial liabilities for which carrying values equal or approximate fair value	0	0
Portion at Other than Fair Value Measurement
Financial assets carried at other than fair value
Card Member and Other loans, less reserves	120,000	113,000
Financial liabilities carried at other than fair value
Certificates of deposit	19,000	16,000
Long-term debt	46,000	42,000
Fair Values (Textuals)
Long-term debt	46,000	42,000
Portion at Other than Fair Value Measurement | Variable Interest Entity, Primary Beneficiary
Financial liabilities carried at other than fair value
Long-term debt	14,400	12,300
Fair Values (Textuals)
Long-term debt	14,400	12,300
Portion at Other than Fair Value Measurement | Variable Interest Entity, Primary Beneficiary | Card Member Loans
Fair Values (Textuals)
Financing receivables, gross	27,400	28,400
Portion at Other than Fair Value Measurement | Level 1
Financial assets carried at other than fair value
Card Member and Other loans, less reserves	0	0
Financial liabilities carried at other than fair value
Certificates of deposit	0	0
Long-term debt	0	0
Fair Values (Textuals)
Long-term debt	0	0
Portion at Other than Fair Value Measurement | Level 2
Financial assets carried at other than fair value
Card Member and Other loans, less reserves	0	0
Financial liabilities carried at other than fair value
Certificates of deposit	19,000	16,000
Long-term debt	46,000	42,000
Fair Values (Textuals)
Long-term debt	46,000	42,000
Portion at Other than Fair Value Measurement | Level 3
Financial assets carried at other than fair value
Card Member and Other loans, less reserves	120,000	113,000
Financial liabilities carried at other than fair value
Certificates of deposit	0	0
Long-term debt	0	0
Fair Values (Textuals)
Long-term debt	$ 0	$ 0