Fair Value (Details 1) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financial Assets Textuals [Abstract]
Card Member receivables HFS	$ 0	$ 24
Financial assets carried at other than fair value [Abstract]
Card Member loans, less reserves	471	431
Loans to affiliates and other	10,659	14,262	$ 15,303
Financial liabilities carried at other than fair value [Abstract]
Long-term Debt	20,512	21,725
Carrying Value [Member]
Financial assets for which carrying values equal or approximate fair value
Cash and cash equivalents	1,200	200
Other financial assets	19,300	18,200
Financial Liabilities:
Financial liabilities for which carrying values equal or approximate fair value	9,100	9,400
Estimate of Fair Value, Fair Value Disclosure [Member]
Financial assets for which carrying values equal or approximate fair value
Cash and cash equivalents	1,200	200
Other financial assets	19,300	18,200
Financial assets carried at other than fair value [Abstract]
Card Member loans, less reserves	500	400
Loans to affiliates and other	10,700	14,300
Financial Liabilities:
Financial liabilities for which carrying values equal or approximate fair value	9,100	9,400
Financial liabilities carried at other than fair value [Abstract]
Long-term Debt	20,700	21,800
Level 1 [Member]
Financial assets for which carrying values equal or approximate fair value
Cash and cash equivalents	200	200
Other financial assets	0	0
Financial assets carried at other than fair value [Abstract]
Card Member loans, less reserves	0	0
Loans to affiliates and other	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 [Abstract]
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	0
Other financial assets	19,300	18,200
Financial assets carried at other than fair value [Abstract]
Card Member loans, less reserves	0	0
Loans to affiliates and other	7,900	11,300
Financial Liabilities:
Financial liabilities for which carrying values equal or approximate fair value	9,100	9,400
Financial liabilities carried at other than fair value [Abstract]
Long-term Debt	20,700	21,800
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 [Abstract]
Card Member loans, less reserves	500	400
Loans to affiliates and other	2,800	3,000
Financial Liabilities:
Financial liabilities for which carrying values equal or approximate fair value	0	0
Financial liabilities carried at other than fair value [Abstract]
Long-term Debt	$ 0	$ 0