Loans - Schedule of Additional Information on Nonaccrual Loans (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Receivables [Abstract]
Residential Mortgage Loan Nonaccrual Carried At Lower Of Amortized Cost Or Fair Value Less Cost To Sell	$ 740		$ 740		$ 817
Interest income that would have been recorded if the nonaccrual receivable had been current in accordance with contractual terms during the period	21	$ 23	65	$ 77
Interest income that was recorded on nonaccrual loans and included in interest income during the period	$ 5	$ 6	$ 17	$ 20