Alternative investments as a percentage of overall invested assets.

No definition available.

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- Definition

Amortized cost of portfolio rated below investment grade.

+ References

No definition available.

+ Details

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- Definition

This item represents the change in gross unrealized holding gain or loss on available-for-sale securities that has been included in accumulated other comprehensive income, a separate component of shareholders' equity, during the period.

+ References

No definition available.

+ Details

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- Definition

Percentage of the fair value of portfolio that was rated investment grade as of balance sheet date.

+ References

No definition available.

+ Details

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- Definition

Fair value of portfolio rated below investment grade.

+ References

No definition available.

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- Definition

Financing receivable, Number of loans past due

+ References

No definition available.

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- Definition

Impaired financing receivable, number of impaired loans

+ References

No definition available.

+ Details

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- Definition

This item represents total investment commitments as of the balance sheet date for fixed maturity available-for-sale securities, limited partnerships, real estate and mortgage loans on real estate.

+ References

No definition available.

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- Definition

This item represents investment commitments as of the balance sheet date for limited partnerships.

+ References

No definition available.

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- Definition

This item represents investment commitments as of the balance sheet date for private placements.

+ References

No definition available.

+ Details

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- Definition

This item represents investment commitments as of the balance sheet date for mortgage loans.

+ References

No definition available.

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- Definition

Investments [Line Items]

+ References

No definition available.

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- Definition

Number of partnerships represented in alternative investment portfolio.

+ References

No definition available.

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- Definition

This item represents the loss severity as a percentage of first lien loans that was considered as one of the potential factors in reaching a conclusion that the available-for-sale investments are other than temporarily impaired and the amount of such impairment determined to be related to credit loss recognized in earnings.

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

This item represents the loss severity as a percentage of defaulted second lien loans that was considered as one of the potential factors in reaching a conclusion that the available-for-sale investments are other than temporarily impaired and the amount of such impairment determined to be related to credit loss recognized in earnings.

+ References

No definition available.

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

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- Definition

This item represents disclosure of all significant concentrations of credit risk or market risk arising from the subject financial instrument (as defined), whether from an individual counterparty or groups of counterparties.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value of collateral permitted, by contact or custom, to be sold or re-pledged.

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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Fair value of the collateral, or portion thereof, that has been re-pledged, delivered, or otherwise used.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

Amount of allowance for credit losses related to recorded investment.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

Amount of investment in impaired financing receivables for which there is a related allowance for credit losses.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

Amount of unrealized holding gain (loss) recognized in the income statement for investments in debt and equity securities and other forms of securities that provide ownership interests classified as trading.

+ References

No definition available.

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Investments (Narrative) (Details) $ in Millions	12 Months Ended
Investments (Narrative) (Details) $ in Millions	Dec. 31, 2019 USD ($) item security	Dec. 31, 2018 USD ($) security item	Dec. 31, 2017 USD ($)
Investments [Line Items]
Decrease in gross AFS securities unrealized losses	$ (2,100)
Unrealized gain (loss), trading securities	$ (225)	$ (55)	$ 8
Number of partnerships in alternative investment portfolio \| security	256	234
Alternative investments as a percentage of overall invested assets	1.00%	1.00%
Fair value of collateral received that we are permitted to sell or re-pledge	$ 25
Securities that have been re-pledged	25
Investment commitments	2,000
Investment commitments for limited partnerships	1,000
Investment commitments for mortgage loans on real estate	544
Investment commitments for private placements	$ 407
Commercial [Member]
Investments [Line Items]
Number of impaired loans \| security	1	0
Commercial [Member] \| Maximum [Member]
Investments [Line Items]
Impaired financing receivable, carrying amount	$ 1
Residential [Member]
Investments [Line Items]
Number of loans past due \| security	38	0
Number of impaired loans \| item	4	0
Impaired financing receivable, allowance	$ 2
Impaired financing receivable, carrying amount	1
Residential [Member] \| Maximum [Member]
Investments [Line Items]
Impaired financing receivable, allowance		$ 1
Federal Home Loan Mortgage Corporation [Member] \| Investments [Member]
Investments [Line Items]
Fair value	$ 1,300	$ 1,400
Concentration risk, percentage	1.00%	1.00%
Fannie Mae [Member] \| Investments [Member]
Investments [Line Items]
Fair value	$ 1,000	$ 1,200
Concentration risk, percentage	1.00%	1.00%
Financial Service [Member] \| Investments [Member]
Investments [Line Items]
Fair value	$ 18,200	$ 16,000
Concentration risk, percentage	14.00%	14.00%
Consumer Non-Cyclical Industry [Member] \| Investments [Member]
Investments [Line Items]
Fair value	$ 15,400	$ 14,300
Concentration risk, percentage	12.00%	13.00%
Mortgage Loans On Real Estate [Member] \| Geographic Concentration Risk [Member] \| Commercial [Member] \| California [Member]
Investments [Line Items]
Concentration risk, percentage	24.00%	23.00%
Mortgage Loans On Real Estate [Member] \| Geographic Concentration Risk [Member] \| Commercial [Member] \| Texas [Member]
Investments [Line Items]
Concentration risk, percentage	11.00%	12.00%
Mortgage Loans On Real Estate [Member] \| Geographic Concentration Risk [Member] \| Residential [Member] \| California [Member]
Investments [Line Items]
Concentration risk, percentage	34.00%	34.00%
Mortgage Loans On Real Estate [Member] \| Geographic Concentration Risk [Member] \| Residential [Member] \| Florida [Member]
Investments [Line Items]
Concentration risk, percentage	20.00%	19.00%
Corporate Bonds [Member]
Investments [Line Items]
Percentage of fair value rated as investment grade	96.00%
Amortized cost of portfolio rated below investment grade	$ 3,100	$ 3,100
Fair value of portfolio rated below investment grade	$ 3,100	$ 2,900
MBS [Member]
Investments [Line Items]
Severity of second lien loans	100.00%
Severity of first lien loans	30.00%