Alternative investments as a percentage of overall invested assets.

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Amortized cost of portfolio rated below investment grade.

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No definition available.

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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.

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No definition available.

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

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No definition available.

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This line item represents the change in deferred acquisition costs, value of business acquired, deferred sales inducements and deferred front-end loads associated with gross other-than-temporary impairment losses recognized in other comprehensive income (loss).

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No definition available.

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Fair value of portfolio rated below investment grade.

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No definition available.

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Impaired financing receivable, number of impaired loans

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No definition available.

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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.

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No definition available.

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

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No definition available.

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

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No definition available.

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

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No definition available.

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Number of partnerships represented in alternative investment portfolio.

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No definition available.

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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.

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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

Line items represent reporting concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
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-Sentence Column A

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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.

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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.

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

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

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Amount of allowance for credit losses related to recorded investment.

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

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Unpaid principal balance of impaired financing receivables for which there is a related allowance for credit losses.

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Amount after tax of other than temporary impairment (OTTI) loss on investments in available-for-sale and held-to-maturity debt securities, recognized in other comprehensive loss.

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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.

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No definition available.

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Investments (Narrative) (Details) $ in Millions	12 Months Ended
Investments (Narrative) (Details) $ in Millions	Dec. 31, 2018 USD ($) security	Dec. 31, 2017 USD ($) security	Dec. 31, 2016 USD ($)
Investment [Line Items]
Increase (decrease) in gross AFS securities unrealized losses	$ 1,900
Unrealized gain (loss), trading securities	$ (55)	$ 8	$ (3)
Number of partnerships in alternative investment portfolio \| security	234	221
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	$ 537
Securities that have been re-pledged	378
Investment commitments	2,100
Investment commitments for limited partnerships	843
Investment commitments for mortgage loans on real estate	804
Investment commitments for private placements	476
OTTI in OCI			53
Change in DAC, VOBA, DSI, and DFEL			$ 12
Maximum [Member]
Investment [Line Items]
OTTI in OCI	$ 1	$ 1
Commercial [Member]
Investment [Line Items]
Number of impaired loans \| security	0	3
Impaired financing receivable, principal balance		$ 11
Impaired financing receivable, allowance		3
Impaired financing receivable, carrying amount		$ 8
Residential [Member]
Investment [Line Items]
Number of impaired loans \| security	0	0
Residential [Member] \| Maximum [Member]
Investment [Line Items]
Impaired financing receivable, allowance	$ 1
Federal Home Loan Mortgage Corporation [Member] \| Invested Assets [Member]
Investment [Line Items]
Fair value	$ 1,400	$ 1,200
Concentration risk, percentage	1.00%	1.00%
Fannie Mae [Member] \| Invested Assets [Member]
Investment [Line Items]
Fair value	$ 1,200	$ 930
Concentration risk, percentage	1.00%	1.00%
Financial Service [Member] \| Invested Assets [Member]
Investment [Line Items]
Fair value	$ 16,000
Concentration risk, percentage	14.00%
Consumer Non-Cyclical Industry [Member] \| Invested Assets [Member]
Investment [Line Items]
Fair value	$ 13,800	$ 14,300
Concentration risk, percentage	12.00%	13.00%
Utilities Industry [Member] \| Invested Assets [Member]
Investment [Line Items]
Fair value		$ 13,800
Concentration risk, percentage		12.00%
Mortgage Loans On Real Estate [Member] \| Geographic Concentration Risk [Member] \| Commercial [Member] \| California [Member]
Investment [Line Items]
Concentration risk, percentage	23.00%	21.00%
Mortgage Loans On Real Estate [Member] \| Geographic Concentration Risk [Member] \| Commercial [Member] \| Texas [Member]
Investment [Line Items]
Concentration risk, percentage	12.00%	12.00%
Mortgage Loans On Real Estate [Member] \| Geographic Concentration Risk [Member] \| Residential [Member]
Investment [Line Items]
Concentration risk, percentage		0.00%
Mortgage Loans On Real Estate [Member] \| Geographic Concentration Risk [Member] \| Residential [Member] \| California [Member]
Investment [Line Items]
Concentration risk, percentage	34.00%
Mortgage Loans On Real Estate [Member] \| Geographic Concentration Risk [Member] \| Residential [Member] \| Florida [Member]
Investment [Line Items]
Concentration risk, percentage	19.00%
Corporate Bonds [Member]
Investment [Line Items]
Percentage of fair value rated as investment grade	96.00%
Amortized cost of portfolio rated below investment grade	$ 3,100	$ 3,400
Fair value of portfolio rated below investment grade	$ 2,900	$ 3,400
MBS [Member]
Investment [Line Items]
Severity of second lien loans	100.00%
Severity of first lien loans	30.00%