Fair Value of Assets and Liabilities - Change in level 3 assets and liabilities (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Gains (losses) included in net income for Level 3 assets and liabilities:
Fair value assets measured on recurring basis, change in unrealized gain (loss) included in earnings	$ 6	$ 36	$ 10
Gains (losses) for Level 3 liabilities still held at the balance sheet date, included in earnings	(61)	58	0
Gains (losses) for Level 3 assets and liabilities still held at the balance sheet date, included in earnings	(55)	94	10
Net investment income
Gains (losses) included in net income for Level 3 assets and liabilities:
Gains (losses) for Level 3 assets still held at the balance sheet date	(2)	0	19
Realized capital gains (losses)
Gains (losses) included in net income for Level 3 assets and liabilities:
Gains (losses) for Level 3 assets still held at the balance sheet date	8	36	(8)
Life and annuity contract benefits
Gains (losses) included in net income for Level 3 assets and liabilities:
Gains (losses) for Level 3 assets still held at the balance sheet date	7	(5)	9
Interest credited to contractholder funds
Gains (losses) included in net income for Level 3 assets and liabilities:
Gains (losses) for Level 3 assets still held at the balance sheet date	(68)	63	(10)
Contractholder funds: Derivatives embedded in life and annuity contracts
Gains (losses) included in net income for Level 3 assets and liabilities:
Gains (losses) for Level 3 liabilities still held at the balance sheet date, included in earnings	(61)	58	0
Municipal
Gains (losses) included in net income for Level 3 assets and liabilities:
Fair value assets measured on recurring basis, change in unrealized gain (loss) included in earnings	1	0	(3)
Corporate
Gains (losses) included in net income for Level 3 assets and liabilities:
Fair value assets measured on recurring basis, change in unrealized gain (loss) included in earnings	0	0	1
Fixed income securities
Gains (losses) included in net income for Level 3 assets and liabilities:
Fair value assets measured on recurring basis, change in unrealized gain (loss) included in earnings	1	0	(2)
Equity securities
Gains (losses) included in net income for Level 3 assets and liabilities:
Fair value assets measured on recurring basis, change in unrealized gain (loss) included in earnings	6	36	13
Free-standing derivatives, net
Gains (losses) included in net income for Level 3 assets and liabilities:
Fair value assets measured on recurring basis, change in unrealized gain (loss) included in earnings	(1)	0	0
Other assets
Gains (losses) included in net income for Level 3 assets and liabilities:
Fair value assets measured on recurring basis, change in unrealized gain (loss) included in earnings	$ 0	$ 0	$ (1)

This item represents the amount of the total change in unrealized (holding) gains or losses for the period which are included in the statement of income (or changes in net assets). Such unrealized (holding) gains or losses relate to those assets and liabilities still held at the reporting date for which fair value is measured on a recurring basis using significant unobservable inputs (Level 3).

No definition available.

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- References

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- Definition

This item represents the amount of the total change in unrealized (holding) gains or losses for the period which are included in the statement of income (or changes in net assets). Such unrealized (holding) gains or losses relate to those assets still held at the reporting date for which fair value is measured on a recurring basis using significant unobservable inputs (Level 3).

+ References

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- Definition

Amount of unrealized gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3) and still held.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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- Definition

Amount of gain (loss) recognized in income from liability measured at fair value on recurring basis using unobservable input (level 3).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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