Consolidated Statement of Income (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Noninterest income
Total recorded as part of gross realized losses	$ 51	$ 26	$ 104	$ 95
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Equity Securities and Nonmarketable Equity Securities	25	104	102	237
Total debt securities [Member]
Noninterest income
Total OTTI losses (reversal of losses) recorded on debt securities	6	11	49	87
Total recorded as part of gross realized losses	48	26	100	91
Total reversal of losses recognized in OCI as non-credit-related impairment	$ (42)	$ (15)	$ (51)	$ (4)