Held-to-maturity Securities (Details - OTTI) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity securities, less than twelve months, fair value	$ 250	$ 3,927
Held-to-maturity securities, twelve months or longer, fair value	1,353	1,629
Held-to-maturity securities, fair value	1,603	5,556
Held-to-maturity securities, less than twelve months, aggregate losses	(2)	(37)
Held-to-maturity securities, twelve months or longer, aggregate losses	(17)	(36)
Held-to-maturity securities, aggregate losses	(19)	(73)
Agency Mortgage-Backed Securities and CMOs [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity securities, less than twelve months, fair value	230	2,807
Held-to-maturity securities, twelve months or longer, fair value	1,353	1,495
Held-to-maturity securities, fair value	1,583	4,302
Held-to-maturity securities, less than twelve months, aggregate losses	(2)	(25)
Held-to-maturity securities, twelve months or longer, aggregate losses	(17)	(33)
Held-to-maturity securities, aggregate losses	(19)	(58)
Agency Debentures [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity securities, less than twelve months, fair value		114
Held-to-maturity securities, fair value		114
Held-to-maturity securities, less than twelve months, aggregate losses		(2)
Held-to-maturity securities, aggregate losses	0	(2)
Agency Debt Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity securities, less than twelve months, fair value	20	1,006
Held-to-maturity securities, twelve months or longer, fair value	0	134
Held-to-maturity securities, fair value	20	1,140
Held-to-maturity securities, less than twelve months, aggregate losses	0	(10)
Held-to-maturity securities, twelve months or longer, aggregate losses	0	(3)
Held-to-maturity securities, aggregate losses	$ 0	$ (13)