Derivatives (Details 2) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
ASSETS
Other assets-Derivative assets, Total	$ 70	$ 26
LIABILITIES
Other liabilities-derivative liabilities, Total	5	2
Not designated as hedging instruments
ASSETS
Gross Assets, subject to master netting agreements	46	29
Gross Assets, Not subject to master netting agreements		22
Gross Assets, Total	93	51
Offsetting Payables	(43)	(2)
Cash Collateral (Received) Paid	20	(23)
Derivative Asset, Fair Value, Amount Offset Against Collateral	23	4
Other assets-Derivative assets, Total	70	26
LIABILITIES
Gross Liabilities, Total	8	2
Offsetting Receivables	(43)	(2)
Cash Collateral Received (Paid)	40	2
Other liabilities-derivative liabilities, Total	5	2
Not designated as hedging instruments | Forward delivery commitments
ASSETS
Gross Assets, subject to master netting agreements	2	2
Gross Assets, Not subject to master netting agreements		1
Offsetting Payables	(2)	(2)
Cash Collateral (Received) Paid	1
Derivative Asset, Fair Value, Amount Offset Against Collateral	1
LIABILITIES
Gross Liabilities, Subject to master netting agreements	7	2
Offsetting Receivables	(7)	(2)
Cash Collateral Received (Paid)	1	2
Derivative Liability, Fair Value, Amount Offset Against Collateral	1	2
Not designated as hedging instruments | MSR-related agreements
ASSETS
Gross Assets, subject to master netting agreements	44	27
Offsetting Payables	(41)
Cash Collateral (Received) Paid	19	(23)
Derivative Asset, Fair Value, Amount Offset Against Collateral	22	4
LIABILITIES
Gross Liabilities, Subject to master netting agreements	1
Offsetting Receivables	(36)
Cash Collateral Received (Paid)	39
Derivative Liability, Fair Value, Amount Offset Against Collateral	4
Not designated as hedging instruments | Interest rate lock commitments
ASSETS
Gross Assets, Not subject to master netting agreements	$ 47	$ 21