Accounting for Derivative Instruments and Hedging Activities (Details - Cash Flow Hedge) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
		Sep. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Impact by Cash Flow Hedge Type on Accumulated Other Comprehensive Income [Abstract]
Termination of legacy wholesale funding obligations		$ 4,400	$ 4,400
Loss on Discontinuation of Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring		$ 370	370	$ 0	$ 0
Impact On Accumulated Other Comprehensive Gain Loss Net Of Tax And Consolidated Statement Of Income [Abstract]
Gains (losses) on derivatives recognized in OCI (effective portion), net of tax	[1]		(10)	(39)	67
Cash Flow Hedging [Member]
Impact by Cash Flow Hedge Type on Accumulated Other Comprehensive Income [Abstract]
Accumulated Other Comprehensive Loss, before Tax				422
Impact On Accumulated Other Comprehensive Gain Loss Net Of Tax And Consolidated Statement Of Income [Abstract]
Gains (losses) on derivatives recognized in OCI (effective portion), net of tax			(10)	(39)	67
Losses reclassified from AOCI into earnings (effective portion), net of tax(1)			(271)	(76)	(87)
Cash flow hedge ineffectiveness gains(2)			$ 0	$ 0	$ 1

[1] Amounts are net of benefit from income taxes of $7 million and $29 million for the years ended December 31, 2015 and 2014, respectively, and net of provision for income taxes of $33 million for the year ended December, 2013.