Derivatives (Details 2) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
ASSETS
Net Amount, asset	$ 49	$ 26
LIABILITIES
Net Amount, liabilities	13	2
Not designated as hedging instruments
ASSETS
Gross Assets, subject to master netting agreements	117	29
Gross Assets, Not subject to master netting agreements	42	22
Gross Assets, Total	159	51
Offsetting Payables	(109)	(2)
Cash Collateral (Received) Paid	(1)	(23)
Derivative Asset, Fair Value, Amount Offset Against Collateral	7	4
Net Amount, asset	49	26
LIABILITIES
Gross Liabilities, Subject to master netting agreements	15
Gross Liabilities, Total	18	2
Offsetting Receivables	(109)	(2)
Cash Collateral Received (Paid)	104	2
Derivative Liability, Fair Value, Amount Offset Against Collateral	10
Net Amount, liabilities	13	2
Not designated as hedging instruments | Forward delivery commitments
ASSETS
Gross Assets, subject to master netting agreements	5	2
Gross Assets, Not subject to master netting agreements	3	1
Offsetting Payables	(5)	(2)
LIABILITIES
Gross Liabilities, Subject to master netting agreements	15	2
Gross Liabilities, Not subject to master netting agreements	3
Offsetting Receivables	(7)	(2)
Cash Collateral Received (Paid)	(6)	2
Derivative Liability, Fair Value, Amount Offset Against Collateral	2	2
Not designated as hedging instruments | MSR-related agreements
ASSETS
Gross Assets, subject to master netting agreements	112	27
Offsetting Payables	(104)
Cash Collateral (Received) Paid	(1)	(23)
Derivative Asset, Fair Value, Amount Offset Against Collateral	7	4
LIABILITIES
Offsetting Receivables	(102)
Cash Collateral Received (Paid)	110
Derivative Liability, Fair Value, Amount Offset Against Collateral	8
Not designated as hedging instruments | Interest rate lock commitments
ASSETS
Gross Assets, Not subject to master netting agreements	$ 39	$ 21