Investments - Narrative (Details) $ in Millions	9 Months Ended
Sep. 30, 2021 USD ($) investment shares	Dec. 31, 2020 USD ($) shares
Debt Securities, Available-for-sale [Line Items]
Accrued interest receivable	$ 255	$ 235
FHLB collateral pledged	$ 2,278	$ 1,622
Commercial mortgage loans, percentage of investments	6.00%
DSC ratio, amortization period	25 years
Number of investments \| investment	1
Cannae Holdings Inc. \| Equity securities
Debt Securities, Available-for-sale [Line Items]
Investment owned, (in shares) \| shares	5,775,598	5,706,134
Investment owned, at fair value	$ 180	$ 253
Residential mortgage loans
Debt Securities, Available-for-sale [Line Items]
Percentage of total investments	100.00%	100.00%
Loans over 90 days past due	$ 1,524	$ 1,159
Over 90 days past due \| Residential mortgage loans
Debt Securities, Available-for-sale [Line Items]
Loans over 90 days past due	80	103
Loans in process of foreclosure	$ 48	24
United States
Debt Securities, Available-for-sale [Line Items]
Residential mortgage loans, location percentage	100.00%
Available-for-sale Securities
Debt Securities, Available-for-sale [Line Items]
Assets held by insurance regulators	$ 21,198	$ 16,714
Residential Mortgage
Debt Securities, Available-for-sale [Line Items]
Percentage of total investments	4.00%

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Number of investments

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Residential Mortgage Loans, Location Percentage

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Percentage of the total residential loan portfolio

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Carrying amount of cash and investment securities on deposit with state regulatory authorities in connection with capital requirements.

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Amount of the collateral pledged in support of federal home loan bank advances outstanding.

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Amount excluding accrued interest, before allowance for credit loss, of financing receivable.

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Carrying amount as of the balance sheet date of interest earned but not received. Also called accrued interest or accrued interest receivable.

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Value of the investment at close of period. For schedules of investments that are categorized, the value would be aggregated by category. For investment in and advances to affiliates, if operations of any controlled companies are different in character from those of the company, group such affiliates within divisions and by type of activities.

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Balance held at close of period in number of shares.

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Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process.

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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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