Derivative Instruments and Hedging Activities (Details - Hedge Ineffectiveness) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
Fair Value Hedge, Hedging Instrument		$ 37	$ 70
Fair Value Hedge, Hedged Item		(51)	(76)
Gain (loss) on interest rate fair value hedge ineffectiveness	$ (19)	(14)	(6)
Agency Debentures [Member]
Derivative [Line Items]
Fair Value Hedge, Hedging Instrument		1	28
Fair Value Hedge, Hedged Item		(3)	(32)
Gain (loss) on interest rate fair value hedge ineffectiveness		(2)	(4)
Agency mortgage-backed securities [Member]
Derivative [Line Items]
Fair Value Hedge, Hedging Instrument		36	42
Fair Value Hedge, Hedged Item		(48)	(44)
Gain (loss) on interest rate fair value hedge ineffectiveness		$ (12)	$ (2)

Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 25
-Section 50
-Paragraph 1
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=109977999&loc=d3e76258-113986

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- Definition

Amount of the increase (decrease) in fair value of the hedged item in a fair value hedge recognized in the income statement.

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The net gain (loss) recognized in earnings during the period due to the ineffectiveness on interest rate fair value hedges.

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