Shareholders' Equity (Details - Accumulated Other Comprehensive Loss Reclassification) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gains (losses) on securities and other									$ (331)	$ 36	$ 61
Operating interest income									1,215	1,279	1,207
Operating interest expense									(129)	(205)	(238)
Income (loss) before income taxes									91	452	195
Income tax (expense) benefit									177	(159)	(109)
Net income	$ 89	$ (153)	$ 292	$ 40	$ 41	$ 86	$ 69	$ 97	268	293	86
Termination of Legacy Wholesale Funding [Line Items]
Termination of legacy wholesale funding obligations		4,400							4,400
Gains (Losses) on early extinguishment of debt		(39)		$ (73)					(112)	(71)	0
Reclassification of deferred losses on cash flow hedges		$ 370							370	0	0
Total Securities Sold Under Agreements To Repurchase And FHLB Advances [Member]
Termination of Legacy Wholesale Funding [Line Items]
Termination of legacy wholesale funding obligations									4,400
Pre-tax charge related to the termination of legacy wholesale funding obligations									413
Gains (Losses) on early extinguishment of debt									(43)
Reclassification of deferred losses on cash flow hedges									370
Available-for-sale Securities | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gains (losses) on securities and other									39	42	60
Income tax (expense) benefit									(15)	(16)	(23)
Net income									24	26	37
Cash Flow Hedging Instruments | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gains (losses) on securities and other									(370)	0	0
Operating interest income									0	0	8
Operating interest expense									(69)	(125)	(147)
Income (loss) before income taxes									(439)	(125)	(139)
Income tax (expense) benefit									168	49	52
Net income									$ (271)	$ (76)	$ (87)