Derivative Financial Instruments Netting of Financial Instruments - Derivatives (Details) - USD ($) $ in Millions		Sep. 30, 2015	Dec. 31, 2014
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset		$ 5,258	$ 5,839
Derivative Asset, Fair Value, Amount Offset Against Collateral		3,809	4,532
Derivative Assets	[1]	1,449	1,307
Collateral Held by The Company Against Derivative Asset Positions		51	63
Derivative Asset, Fair Value, Amount Not Offset Against Collateral		1,398	1,244
Derivative Liability, Fair Value, Gross Liability		4,930	5,577
Derivative Liability, Fair Value, Amount Offset Against Collateral		4,365	5,115
Derivative Liabilities	[2]	565	462
Derivative, Collateral, Right to Reclaim Securities		20	12
Derivative Liability, Fair Value, Amount Not Offset Against Collateral		545	450
Derivatives Subject to Master Netting Arrangement or Similar Arrangement [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset		4,748	5,127
Derivative Asset, Fair Value, Amount Offset Against Collateral		3,455	4,095
Derivative Assets		1,293	1,032
Collateral Held by The Company Against Derivative Asset Positions		51	63
Derivative Asset, Fair Value, Amount Not Offset Against Collateral		1,242	969
Derivative Liability, Fair Value, Gross Liability		4,488	5,001
Derivative Liability, Fair Value, Amount Offset Against Collateral		4,011	4,678
Derivative Liabilities		477	323
Derivative, Collateral, Right to Reclaim Securities		20	12
Derivative Liability, Fair Value, Amount Not Offset Against Collateral		457	311
Derivatives Not Subject to Master Netting Arrangement or Similar Arrangement [Member] [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		38	25
Derivative Asset, Fair Value, Amount Offset Against Collateral		0	0
Derivative Assets		38	25
Collateral Held by The Company Against Derivative Asset Positions		0	0
Derivative Asset, Fair Value, Amount Not Offset Against Collateral		38	25
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		88	133
Derivative Liability, Fair Value, Amount Offset Against Collateral		0	0
Derivative Liabilities		88	133
Derivative, Collateral, Right to Reclaim Securities		0	0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral		88	133
Exchange Traded [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset		472	687
Derivative Asset, Fair Value, Amount Offset Against Collateral		354	437
Derivative Assets		118	250
Collateral Held by The Company Against Derivative Asset Positions		0	0
Derivative Asset, Fair Value, Amount Not Offset Against Collateral		118	250
Derivative Liability, Fair Value, Gross Liability		354	443
Derivative Liability, Fair Value, Amount Offset Against Collateral		354	437
Derivative Liabilities		0	6
Derivative, Collateral, Right to Reclaim Securities		0	0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral		$ 0	$ 6

[1] At September 30, 2015, $1.4 billion, net of $541 million offsetting cash collateral, is recognized in trading assets and derivative instruments within the Company's Consolidated Balance Sheets. At December 31, 2014, $1.3 billion, net of $449 million offsetting cash collateral, is recognized in trading assets and derivative instruments within the Company's Consolidated Balance Sheets.

[2] At September 30, 2015, $565 million, net of $1.1 billion offsetting cash collateral, is recognized in trading liabilities and derivative instruments within the Company's Consolidated Balance Sheets. At December 31, 2014, $462 million, net of $1.0 billion offsetting cash collateral, is recognized in trading liabilities and derivative instruments within the Company's Consolidated Balance Sheets.