Derivative Financial Instruments Netting of Financial Instruments - Derivatives (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 5,463		$ 6,125
Derivative Asset, Fair Value, Amount Offset Against Collateral	4,282		4,741
Derivative Assets	1,181	[1]	1,384	[1]
Collateral Held by The Company Against Derivative Asset Positions	51		51
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	1,130		1,333
Derivative Liability, Fair Value, Gross Liability	5,139		5,673
Derivative Liability, Fair Value, Amount Offset Against Collateral	4,770		5,148
Derivative Liabilities	369	[2]	525	[2]
Financial Instruments, Owned and Pledged as Collateral, at Fair Value	18		13
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	351		512
Derivatives Subject to Master Netting Arrangement or Similar Arrangement [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	4,733		5,285
Derivative Asset, Fair Value, Amount Offset Against Collateral	3,789		4,239
Derivative Assets	944		1,046
Collateral Held by The Company Against Derivative Asset Positions	51		51
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	893		995
Derivative Liability, Fair Value, Gross Liability	4,468		4,982
Derivative Liability, Fair Value, Amount Offset Against Collateral	4,277		4,646
Derivative Liabilities	191		336
Financial Instruments, Owned and Pledged as Collateral, at Fair Value	18		13
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	173		323
Derivatives Not Subject to Master Netting Arrangement or Similar Arrangement [Member] [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	14		12
Derivative Asset, Fair Value, Amount Offset Against Collateral	0		0
Derivative Assets	14		12
Collateral Held by The Company Against Derivative Asset Positions	0		0
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	14		12
Derivative Liability, Fair Value, Gross Liability	178		189
Derivative Liability, Fair Value, Amount Offset Against Collateral	0		0
Derivative Liabilities	178		189
Financial Instruments, Owned and Pledged as Collateral, at Fair Value	0		0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	178		189
Exchange Traded [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	716		828
Derivative Asset, Fair Value, Amount Offset Against Collateral	493		502
Derivative Assets	223		326
Collateral Held by The Company Against Derivative Asset Positions	0		0
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	223		326
Derivative Liability, Fair Value, Gross Liability	493		502
Derivative Liability, Fair Value, Amount Offset Against Collateral	493		502
Derivative Liabilities	0		0
Financial Instruments, Owned and Pledged as Collateral, at Fair Value	0		0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	$ 0		$ 0

[1] At March 31, 2014, $1.2 billion, net of $355 million offsetting cash collateral, is recognized in trading assets and derivatives within the Company's Consolidated Balance Sheets. At December 31, 2013, $1.4 billion, net of $457 million offsetting cash collateral, is recognized in trading assets and derivatives within the Company's Consolidated Balance Sheets.

[2] At March 31, 2014, $369 million, net of $843 million offsetting cash collateral, is recognized in trading liabilities and derivatives within the Company's Consolidated Balance Sheets. At December 31, 2013, $525 million, net of $864 million offsetting cash collateral, is recognized in trading liabilities and derivatives within the Company's Consolidated Balance Sheets.