Securities Financing Arrangements (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Derivative assets
Gross Amounts of Recognized Assets/Liabilities	$ 1,502	$ 1,626
Gross Amounts Offset in Balance Sheet	787	770
Net Amounts Presented in Balance Sheet	715	856
Gross Amounts Not Offset In Balance Sheet, Financial Instruments	44	20
Gross Amounts Not Offset in Balance Sheet, Cash Collateral Received/Pledged	2	0
Net Amount	669	836
Securities borrowed or purchased under resale agreements
Gross Amounts of Recognized Assets/Liabilities	31,147	31,386
Gross Amounts Offset in Balance Sheet	11,155	11,639
Net Amounts Presented in Balance Sheet	19,992	19,747
Securities Purchased under Agreements to Resell, Collateral, Obligation to Return Securities	19,896	19,657
Securities Purchased under Agreements to Resell, Collateral, Obligation to Return Cash	0	0
Net Amount	96	90
Total Financial Assets
Gross Amounts of Recognized Assets/Liabilities	32,649	33,012
Gross Amounts Offset in Balance Sheet	11,942	12,409
Net Amounts Presented in Balance Sheet	20,707	20,603
Gross Amounts Not Offset In Balance Sheet, Financial Instruments	19,940	19,677
Gross Amounts Not Offset in Balance Sheet, Cash Collateral Received/Pledged	2	0
Net Amount	765	926
Derivative liabilities
Gross Amounts of Recognized Assets/Liabilities	1,533	1,684
Gross Amounts Offset in Balance Sheet	968	1,047
Net Amounts Presented in Balance Sheet	565	637
Gross Amount Not Offset in Balance Sheet, Financial Instruments	170	176
Gross Amounts Not Offset in Balance Sheet, Cash Collateral Received/Pledged	0	5
Net Amount	395	456
Securities loaned or sold under repurchase agreements
Securities sold under agreements to repurchase	36,235	36,255
Securities Sold under Agreements to Repurchase, Asset	11,156	11,639
Net Amounts Presented in Balance Sheet	25,079	24,616
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Securities	24,470	23,812
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Cash	0	0
Net Amount	609	804
Total Financial Liabilities
Gross Amounts of Recognized Assets/Liabilities	37,768	37,939
Gross Amounts Offset in Balance Sheet	12,124	12,686
Net Amounts Presented in Balance Sheet	25,644	25,253
Gross Amount Not Offset in Balance Sheet, Financial Instruments	24,640	23,988
Gross Amounts Not Offset in Balance Sheet, Cash Collateral Received/Pledged	0	5
Net Amount	$ 1,004	$ 1,260