Investments - Scheduled maturities of available for sale fixed maturities (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2023	Dec. 31, 2022
Fair Value, Fiscal Year Maturity [Abstract]
Fair Value	$ 10,044	$ 10,095
Fair Value Percent, Fiscal Year Maturity [Abstract]
Average life of ABS	3 years
Average life of MBS	6 years
Fixed maturities
Amortized Cost Basis, Fiscal Year Maturity [Abstract]
One year or less	$ 350
After one year through five years	2,633
After five years through ten years	1,043
After ten years	384
Fixed maturities amortized cost, Subtotal	4,410
Collateralized loan obligations and other ABS (average life of approximately 3 years)	4,336
MBS (average life of approximately 6 years)	1,821
Amortized Cost	10,567
Fair Value, Fiscal Year Maturity [Abstract]
One year or less	345
After one year through five years	2,514
After five years through ten years	1,008
After ten years	370
Fixed maturities fair value, Subtotal	4,237
Collateralized loan obligations and other ABS (average life of approximately 3 years)	4,140
MBS (average life of approximately 6 years)	1,667
Fair Value	$ 10,044	$ 10,095
Fair Value Percent, Fiscal Year Maturity [Abstract]
One year or less	3.00%
After one year through five years	25.00%
After five years through ten years	10.00%
After ten years	4.00%
Fixed maturities fair value, Subtotal, Percent	42.00%
Collateralized loan obligations and other ABS (average life of approximately 3 years)	41.00%
MBS (average life of approximately 6 years)	17.00%
Fair value, Total, Percent	100.00%

Available-for-sale Securities, Debt Maturities, after Five Through Ten Years, Fair Value, Percent.

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Available-for-sale Securities, Debt Maturities, after One Through Five Years, Fair Value, Percent.

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Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value, Percent.

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Available for sale securities debt maturities excluding ABS and MBS amortized cost.

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Available for sale securities debt maturities excluding ABS and MBS fair value.

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Available for sale securities debt maturities excluding ABS and MBS fair value percent.

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Available-for-sale Securities, Debt Maturities, Fair Value, Total, Percent.

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Available For Sale Securities, Debt Maturities, Fair Value Percent, Fiscal Year Maturity [Abstract]

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Available-for-sale Securities, Debt Maturities, within One Year, Fair Value, Percent.

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Mortgage-backed securities, amortized cost.

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Mortgage-backed securities, fair value, percent.

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Collateralized loan obligations and Other asset-backed securities average useful life.

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Collateralized loan obligations and Other asset-backed securities, amortized cost.

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Collateralized loan obligations and other Asset-backed securities, fair value.

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Collateralized loan obligations and other Asset-backed securities, fair value, percent.

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Mortgage backed securities average useful life.

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in sixth through tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in sixth through tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in second through fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in second through fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing after tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing after tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost, after allowance for credit loss, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Fair value of securitized, pay-through debt securities collateralized by real estate mortgage loans classified as available-for-sale.

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