Derivatives (Fair Value Hedges) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivative Gains (Losses) Recognized for Derivatives	$ (64)	$ (14)	$ (56)
Net Derivative Gains (Losses) Recognized for Hedged Items	76	104	42
Ineffectiveness Recognized in Net Derivative Gains (Losses)	12	90	(14)
Interest rate swaps \| Fixed Maturity Securities
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivative Gains (Losses) Recognized for Derivatives	1	4	7
Net Derivative Gains (Losses) Recognized for Hedged Items	(1)	(4)	(9)
Ineffectiveness Recognized in Net Derivative Gains (Losses)	0	0	(2)
Interest rate swaps \| Policyholder account balances [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivative Gains (Losses) Recognized for Derivatives	(221)	(69)	(108)
Net Derivative Gains (Losses) Recognized for Hedged Items	227	134	90
Ineffectiveness Recognized in Net Derivative Gains (Losses)	6	65	(18)
Foreign currency swaps \| Foreign-denominated fixed maturity securities AFS and mortgage loans
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivative Gains (Losses) Recognized for Derivatives	55	(27)	13
Net Derivative Gains (Losses) Recognized for Hedged Items	(57)	29	(12)
Ineffectiveness Recognized in Net Derivative Gains (Losses)	(2)	2	1
Foreign currency swaps \| Foreign-denominated policyholder account balances [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivative Gains (Losses) Recognized for Derivatives	23	65	(95)
Net Derivative Gains (Losses) Recognized for Hedged Items	(23)	(44)	92
Ineffectiveness Recognized in Net Derivative Gains (Losses)	0	21	(3)
Foreign currency forwards \| Foreign-denominated fixed maturity securities AFS and mortgage loans
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivative Gains (Losses) Recognized for Derivatives	78	13	127
Net Derivative Gains (Losses) Recognized for Hedged Items	(70)	(11)	(119)
Ineffectiveness Recognized in Net Derivative Gains (Losses)	$ 8	$ 2	$ 8

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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Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

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