Fair Values (Details 2) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Financial assets for which carrying values equal or approximate fair value
Cash and cash equivalents	$ 22,762	$ 22,288	$ 19,486	$ 22,250
Financial assets carried at other than fair value
Card Member loans and receivables held for sale	14,992	0
Financial liabilities carried at other than fair value
Certificates of deposit	14,144
Long-term debt	48,061	57,955
Fair Values (Textuals) [Abstract]
Accounts receivable, less reserves	43,671	44,386
Card Member loans, net	57,545	69,184
Variable Interest Enterprise [Member]
Financial assets carried at other than fair value
Card Member loans and receivables held for sale	4,966	0
Financial liabilities carried at other than fair value
Long-term debt	13,602	19,516
Fair Values (Textuals) [Abstract]
Accounts receivable, less reserves	6,700	7,000
Carrying Value [Member]
Financial assets for which carrying values equal or approximate fair value
Cash and cash equivalents	23,000	22,000
Other financial assets	47,000	48,000
Financial assets carried at other than fair value
Loans, net	59,000	70,000
Financial Liabilities:
Financial liabilities for which carrying values equal or approximate fair value	67,000	61,000
Financial liabilities carried at other than fair value
Certificates of deposit	14,000	8,000
Long-term debt	48,000	58,000
Estimate of Fair Value, Fair Value Disclosure [Member]
Financial assets for which carrying values equal or approximate fair value
Cash and cash equivalents	23,000	22,000
Other financial assets	47,000	48,000
Financial assets carried at other than fair value
Loans, net	60,000	71,000
Financial Liabilities:
Financial liabilities for which carrying values equal or approximate fair value	67,000	61,000
Financial liabilities carried at other than fair value
Certificates of deposit	14,000	8,000
Long-term debt	49,000	60,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Variable Interest Enterprise [Member]
Financial liabilities carried at other than fair value
Long-term debt	13,600	19,500
Fair Values (Textuals) [Abstract]
Card Member loans, net	23,500	29,900
Level 1 [Member]
Financial assets for which carrying values equal or approximate fair value
Cash and cash equivalents	22,000	21,000
Other financial assets	0	0
Financial assets carried at other than fair value
Loans, net	0	0
Financial Liabilities:
Financial liabilities for which carrying values equal or approximate fair value	0	0
Financial liabilities carried at other than fair value
Certificates of deposit	0	0
Long-term debt	0	0
Level 2 [Member]
Financial assets for which carrying values equal or approximate fair value
Cash and cash equivalents	1,000	1,000
Other financial assets	47,000	48,000
Financial assets carried at other than fair value
Loans, net	0	0
Financial Liabilities:
Financial liabilities for which carrying values equal or approximate fair value	67,000	61,000
Financial liabilities carried at other than fair value
Certificates of deposit	14,000	8,000
Long-term debt	49,000	60,000
Level 3 [Member]
Financial assets for which carrying values equal or approximate fair value
Cash and cash equivalents	0	0
Other financial assets	0	0
Financial assets carried at other than fair value
Loans, net	60,000	71,000
Financial Liabilities:
Financial liabilities for which carrying values equal or approximate fair value	0	0
Financial liabilities carried at other than fair value
Certificates of deposit	0	0
Long-term debt	$ 0	$ 0