Investments - Scheduled maturities of available for sale fixed maturities (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Fair Value, Fiscal Year Maturity [Abstract]
Fair Value	$ 10,357	$ 9,084
Fair Value Percent, Fiscal Year Maturity [Abstract]
Collateralized loan obligations and other asset-backed securities average life	3 years
Average life of MBS	3 years 6 months
Fixed maturities
Amortized Cost Basis, Fiscal Year Maturity [Abstract]
One year or less	$ 1,228
After one year through five years	2,483
After five years through ten years	812
After ten years	332
Fixed maturities amortized cost, Subtotal	4,855
Collateralized loan obligations and other ABS (average life of approximately 3 years)	4,312
MBS (average life of approximately 3.5 years)	1,017
Amortized Cost	10,184
Fair Value, Fiscal Year Maturity [Abstract]
One year or less	1,240
After one year through five years	2,548
After five years through ten years	844
After ten years	342
Fixed maturities fair value, Subtotal	4,974
Collateralized loan obligations and other ABS (average life of approximately 3 years)	4,319
MBS (average life of approximately 3.5 years)	1,064
Fair Value	$ 10,357	$ 9,084
Fair Value Percent, Fiscal Year Maturity [Abstract]
One year or less	12.00%
After one year through five years	25.00%
After five years through ten years	8.00%
After ten years	3.00%
Fixed maturities fair value, Subtotal, Percent	48.00%
Collateralized loan obligations and other ABS (average life of approximately 3 years)	42.00%
MBS (average life of approximately 3.5 years)	10.00%
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, 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 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 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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