Reinsurance - Reinsurance Recoverables by Range of External Credit Rating and Collateral Level (Details) $ in Millions	Mar. 31, 2022 USD ($)
Ceded Credit Risk [Line Items]
Reinsurance recoverables	$ 5,205
Allowance for uncollectible reinsurance	(30)
Total reinsurance recoverables	5,175
Fair value of collateral contractually required to meet or exceed carrying value of recoverable
Ceded Credit Risk [Line Items]
Reinsurance recoverables	1,156
Collateral provisions exist that may mitigate risk of credit loss
Ceded Credit Risk [Line Items]
Reinsurance recoverables	3,750
No collateral
Ceded Credit Risk [Line Items]
Reinsurance recoverables	299
Ongoing Operations
Ceded Credit Risk [Line Items]
Reinsurance recoverables	396
Ongoing Operations | A- equivalent and higher current ratings (
Ceded Credit Risk [Line Items]
Reinsurance recoverables	176
Ongoing Operations | BBB- to BBB+ equivalent current credit ratings
Ceded Credit Risk [Line Items]
Reinsurance recoverables	61
Ongoing Operations | Not rated
Ceded Credit Risk [Line Items]
Reinsurance recoverables	159
Ongoing Operations | Fair value of collateral contractually required to meet or exceed carrying value of recoverable
Ceded Credit Risk [Line Items]
Reinsurance recoverables	116
Ongoing Operations | Fair value of collateral contractually required to meet or exceed carrying value of recoverable | A- equivalent and higher current ratings (
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Ongoing Operations | Fair value of collateral contractually required to meet or exceed carrying value of recoverable | BBB- to BBB+ equivalent current credit ratings
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Ongoing Operations | Fair value of collateral contractually required to meet or exceed carrying value of recoverable | Not rated
Ceded Credit Risk [Line Items]
Reinsurance recoverables	116
Ongoing Operations | Collateral provisions exist that may mitigate risk of credit loss
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Ongoing Operations | Collateral provisions exist that may mitigate risk of credit loss | A- equivalent and higher current ratings (
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Ongoing Operations | Collateral provisions exist that may mitigate risk of credit loss | BBB- to BBB+ equivalent current credit ratings
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Ongoing Operations | Collateral provisions exist that may mitigate risk of credit loss | Not rated
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Ongoing Operations | No collateral
Ceded Credit Risk [Line Items]
Reinsurance recoverables	280
Ongoing Operations | No collateral | A- equivalent and higher current ratings (
Ceded Credit Risk [Line Items]
Reinsurance recoverables	176
Ongoing Operations | No collateral | BBB- to BBB+ equivalent current credit ratings
Ceded Credit Risk [Line Items]
Reinsurance recoverables	61
Ongoing Operations | No collateral | Not rated
Ceded Credit Risk [Line Items]
Reinsurance recoverables	43
Acquisition, disposition or run-off activities
Ceded Credit Risk [Line Items]
Reinsurance recoverables	4,809
Acquisition, disposition or run-off activities | A- equivalent and higher current ratings ( | Lincoln National Life and Lincoln Life & Annuity of New York
Ceded Credit Risk [Line Items]
Reinsurance recoverables	2,908
Acquisition, disposition or run-off activities | A- equivalent and higher current ratings ( | Berkshire Hathaway Life Insurance Company of Nebraska
Ceded Credit Risk [Line Items]
Reinsurance recoverables	644
Acquisition, disposition or run-off activities | A- equivalent and higher current ratings ( | Prudential Retirement Insurance and Annuity
Ceded Credit Risk [Line Items]
Reinsurance recoverables	149
Acquisition, disposition or run-off activities | A- equivalent and higher current ratings ( | Prudential Insurance Company of America
Ceded Credit Risk [Line Items]
Reinsurance recoverables	404
Acquisition, disposition or run-off activities | A- equivalent and higher current ratings ( | Life Insurance Company of North America
Ceded Credit Risk [Line Items]
Reinsurance recoverables	437
Acquisition, disposition or run-off activities | A- equivalent and higher current ratings ( | Other
Ceded Credit Risk [Line Items]
Reinsurance recoverables	251
Acquisition, disposition or run-off activities | Not rated
Ceded Credit Risk [Line Items]
Reinsurance recoverables	16
Acquisition, disposition or run-off activities | Fair value of collateral contractually required to meet or exceed carrying value of recoverable
Ceded Credit Risk [Line Items]
Reinsurance recoverables	1,040
Acquisition, disposition or run-off activities | Fair value of collateral contractually required to meet or exceed carrying value of recoverable | A- equivalent and higher current ratings ( | Lincoln National Life and Lincoln Life & Annuity of New York
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Acquisition, disposition or run-off activities | Fair value of collateral contractually required to meet or exceed carrying value of recoverable | A- equivalent and higher current ratings ( | Berkshire Hathaway Life Insurance Company of Nebraska
Ceded Credit Risk [Line Items]
Reinsurance recoverables	268
Acquisition, disposition or run-off activities | Fair value of collateral contractually required to meet or exceed carrying value of recoverable | A- equivalent and higher current ratings ( | Prudential Retirement Insurance and Annuity
Ceded Credit Risk [Line Items]
Reinsurance recoverables	149
Acquisition, disposition or run-off activities | Fair value of collateral contractually required to meet or exceed carrying value of recoverable | A- equivalent and higher current ratings ( | Prudential Insurance Company of America
Ceded Credit Risk [Line Items]
Reinsurance recoverables	404
Acquisition, disposition or run-off activities | Fair value of collateral contractually required to meet or exceed carrying value of recoverable | A- equivalent and higher current ratings ( | Life Insurance Company of North America
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Acquisition, disposition or run-off activities | Fair value of collateral contractually required to meet or exceed carrying value of recoverable | A- equivalent and higher current ratings ( | Other
Ceded Credit Risk [Line Items]
Reinsurance recoverables	219
Acquisition, disposition or run-off activities | Fair value of collateral contractually required to meet or exceed carrying value of recoverable | Not rated
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Acquisition, disposition or run-off activities | Collateral provisions exist that may mitigate risk of credit loss
Ceded Credit Risk [Line Items]
Reinsurance recoverables	3,750
Acquisition, disposition or run-off activities | Collateral provisions exist that may mitigate risk of credit loss | A- equivalent and higher current ratings ( | Lincoln National Life and Lincoln Life & Annuity of New York
Ceded Credit Risk [Line Items]
Reinsurance recoverables	2,908
Acquisition, disposition or run-off activities | Collateral provisions exist that may mitigate risk of credit loss | A- equivalent and higher current ratings ( | Berkshire Hathaway Life Insurance Company of Nebraska
Ceded Credit Risk [Line Items]
Reinsurance recoverables	376
Acquisition, disposition or run-off activities | Collateral provisions exist that may mitigate risk of credit loss | A- equivalent and higher current ratings ( | Prudential Retirement Insurance and Annuity
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Acquisition, disposition or run-off activities | Collateral provisions exist that may mitigate risk of credit loss | A- equivalent and higher current ratings ( | Prudential Insurance Company of America
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Acquisition, disposition or run-off activities | Collateral provisions exist that may mitigate risk of credit loss | A- equivalent and higher current ratings ( | Life Insurance Company of North America
Ceded Credit Risk [Line Items]
Reinsurance recoverables	437
Acquisition, disposition or run-off activities | Collateral provisions exist that may mitigate risk of credit loss | A- equivalent and higher current ratings ( | Other
Ceded Credit Risk [Line Items]
Reinsurance recoverables	16
Acquisition, disposition or run-off activities | Collateral provisions exist that may mitigate risk of credit loss | Not rated
Ceded Credit Risk [Line Items]
Reinsurance recoverables	13
Acquisition, disposition or run-off activities | No collateral
Ceded Credit Risk [Line Items]
Reinsurance recoverables	19
Acquisition, disposition or run-off activities | No collateral | A- equivalent and higher current ratings ( | Lincoln National Life and Lincoln Life & Annuity of New York
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Acquisition, disposition or run-off activities | No collateral | A- equivalent and higher current ratings ( | Berkshire Hathaway Life Insurance Company of Nebraska
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Acquisition, disposition or run-off activities | No collateral | A- equivalent and higher current ratings ( | Prudential Retirement Insurance and Annuity
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Acquisition, disposition or run-off activities | No collateral | A- equivalent and higher current ratings ( | Prudential Insurance Company of America
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Acquisition, disposition or run-off activities | No collateral | A- equivalent and higher current ratings ( | Life Insurance Company of North America
Ceded Credit Risk [Line Items]
Reinsurance recoverables	0
Acquisition, disposition or run-off activities | No collateral | A- equivalent and higher current ratings ( | Other
Ceded Credit Risk [Line Items]
Reinsurance recoverables	16
Acquisition, disposition or run-off activities | No collateral | Not rated
Ceded Credit Risk [Line Items]
Reinsurance recoverables	$ 3