Derivative Financial Instruments Netting of Financial Instruments - Derivatives (Additional Information) (Details) - USD ($) $ in Millions		Jun. 30, 2015	Dec. 31, 2014
Derivative [Line Items]
Derivative Assets	[1]	$ 1,208	$ 1,307
Derivative Liabilities	[2]	400	462
Trading Liabilities [Member]
Derivative [Line Items]
Derivative Liabilities		400	462
Derivative Liability, Fair Value of Collateral		(1,099)	(1,032)
Trading Account Assets [Member]
Derivative [Line Items]
Derivative Assets		1,200	1,300
Derivative Asset, Fair Value of Collateral		$ (411)	$ (449)

[1] At June 30, 2015, $1.2 billion, net of $411 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 June 30, 2015, $400 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.