Deposit Liabilities Deposit Liabilities (Schedule of Maturities for Total Time Deposits) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Schedule of Maturities For Total Time Deposits [Line Items]
Time Deposits	$ 31,795	$ 29,774
One year, or less [Member]
Schedule of Maturities For Total Time Deposits [Line Items]
Time Deposits	16,206
Two years, or less [Member]
Schedule of Maturities For Total Time Deposits [Line Items]
Time Deposits	9,984
Three years, or less [Member]
Schedule of Maturities For Total Time Deposits [Line Items]
Time Deposits	3,041
Four years, or less [Member]
Schedule of Maturities For Total Time Deposits [Line Items]
Time Deposits	1,348
Five years or less [Member]
Schedule of Maturities For Total Time Deposits [Line Items]
Time Deposits	$ 1,216