Investments (Narrative) (Details) $ in Millions	3 Months Ended	12 Months Ended	15 Months Ended
Mar. 31, 2022 USD ($) loan item	Dec. 31, 2021 USD ($) loan item	Mar. 31, 2022 USD ($) loan item
Schedule of Investments [Line Items]
Decrease in gross AFS securities unrealized gains (losses)	$ 2,500
Number of partnerships in alternative investment portfolio \| item	309	305	309
Alternative investments as a percentage of overall invested assets	2.00%	2.00%
Fair value of collateral received that we are permitted to sell or re-pledge	$ 22		$ 22
Investment commitments	3,100		3,100
Investment commitments for limited partnerships	1,500		1,500
Investment commitments for private placements	740		740
Investment commitments for mortgage loans on real estate	$ 842		$ 842
Minimum [Member]
Schedule of Investments [Line Items]
Percentage of the fair value of securities obtained as collateral under reverse repurchase agreements.	80.00%		80.00%
Maximum [Member]
Schedule of Investments [Line Items]
Percentage of the fair value of securities obtained as collateral under reverse repurchase agreements.	95.00%		95.00%
Financial Service [Member] \| Investments [Member]
Schedule of Investments [Line Items]
Fair value	$ 20,800	$ 21,700	$ 20,800
Consumer Non-Cyclical Industry [Member] \| Investments [Member]
Schedule of Investments [Line Items]
Fair value	$ 16,800	$ 18,600	$ 16,800
Mortgage Loans On Real Estate [Member] \| Geographic Concentration [Member] \| Commercial [Member] \| California [Member]
Schedule of Investments [Line Items]
Concentration risk, percentage	26.00%	26.00%
Mortgage Loans On Real Estate [Member] \| Geographic Concentration [Member] \| Commercial [Member] \| Texas [Member]
Schedule of Investments [Line Items]
Concentration risk, percentage			9.00%
Mortgage Loans On Real Estate [Member] \| Geographic Concentration [Member] \| Residential [Member] \| California [Member]
Schedule of Investments [Line Items]
Concentration risk, percentage	21.00%	22.00%
Mortgage Loans On Real Estate [Member] \| Geographic Concentration [Member] \| Residential [Member] \| Florida [Member]
Schedule of Investments [Line Items]
Concentration risk, percentage	12.00%	14.00%
Corporate Bonds [Member]
Schedule of Investments [Line Items]
Percentage of fair value rated as investment grade	96.00%	96.00%	96.00%
Amortized cost of portfolio rated below investment grade	$ 3,500	$ 3,500	$ 3,500
Fair value of portfolio rated below investment grade	$ 3,500	$ 3,700	$ 3,500
Mortgage Loans On Real Estate [Member] \| Commercial [Member]
Schedule of Investments [Line Items]
Number of impaired loans \| loan	4	4	4
Impaired financing receivable, principal balance	$ 1	$ 1	$ 1
Mortgage Loans On Real Estate [Member] \| Residential [Member]
Schedule of Investments [Line Items]
Number of loans past due \| loan	63	65	63
Financing Receivable, Number of Loans In Foreclosure \| loan	38	34	38
Financing Receivable, 90 Days or More Past Due, Still Accruing	$ 17	$ 15	$ 17
Number of impaired loans \| loan	46	50	46
Impaired financing receivable, principal balance	$ 18	$ 22	$ 18
Fixed Maturity AFS Securities [Member] \| Federal Home Loan Mortgage Corporation [Member] \| Investments [Member]
Schedule of Investments [Line Items]
Fair value	$ 817	$ 910	817
Concentration risk, percentage	1.00%	1.00%
Fixed Maturity AFS Securities [Member] \| White Chapel LLC [Member] \| Investments [Member]
Schedule of Investments [Line Items]
Fair value	$ 1,000	$ 995	$ 1,000
Concentration risk, percentage	1.00%	1.00%
Fixed Maturity AFS Securities [Member] \| Financial Service [Member] \| Investments [Member]
Schedule of Investments [Line Items]
Concentration risk, percentage	15.00%	14.00%
Fixed Maturity AFS Securities [Member] \| Consumer Non-Cyclical Industry [Member] \| Investments [Member]
Schedule of Investments [Line Items]
Concentration risk, percentage	12.00%	12.00%

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

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This item represents the percentage of the fair value of securities obtained as collateral under reverse repurchase agreements

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Fair value of portfolio rated below investment grade.

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Financing Receivable, Number of Loans In Foreclosure

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Financing receivable, Number of loans past due

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Impaired financing receivable, number of impaired loans

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

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

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

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Number of partnerships represented in alternative investment portfolio.

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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.

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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.

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- Definition

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

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- Definition

Amount of financing receivable 90 days or more past due and still accruing.

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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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- Definition

Line items represent financial 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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