Reinsurance - Reinsurance Recoverables (Details) - USD ($) $ in Millions | Mar. 31, 2024 | Mar. 31, 2023 |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | $ 4,131 | |
Allowance for uncollectible reinsurance, including assets held for sale | (35) | |
Market risk benefits | 951 | $ 1,301 |
Total reinsurance recoverables, including assets held for sale | 5,047 | |
Held-for-Sale | Medicare Advantage and related Cigna Healthcare businesses | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverable classified as assets of businesses held for sale | 209 | |
Other Current Assets | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables | 166 | |
Berkshire Hathway Life Insurance Company Of Nebraska and Other Recoverables | | |
Ceded Credit Risk [Line Items] | | |
Market risk benefits | 951 | |
Fair value of collateral contractually required to meet or exceed carrying value of recoverable | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 663 | |
Collateral provisions exist that may mitigate risk of credit loss | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 2,989 | |
No collateral | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 479 | |
Ongoing Operations | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 485 | |
Ongoing Operations | A- equivalent and higher current ratings | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 85 | |
Ongoing Operations | BBB- to BBB+ equivalent current credit ratings | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 60 | |
Ongoing Operations | Not rated | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 340 | |
Ongoing Operations | Fair value of collateral contractually required to meet or exceed carrying value of recoverable | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 145 | |
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 before market risk benefits, including assets held for sale | 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 before market risk benefits, including assets held for sale | 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 before market risk benefits, including assets held for sale | 145 | |
Ongoing Operations | Collateral provisions exist that may mitigate risk of credit loss | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 7 | |
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 before market risk benefits, including assets held for sale | 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 before market risk benefits, including assets held for sale | 0 | |
Ongoing Operations | Collateral provisions exist that may mitigate risk of credit loss | Not rated | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 7 | |
Ongoing Operations | No collateral | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 333 | |
Ongoing Operations | No collateral | A- equivalent and higher current ratings | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 85 | |
Ongoing Operations | No collateral | BBB- to BBB+ equivalent current credit ratings | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 60 | |
Ongoing Operations | No collateral | Not rated | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 188 | |
Acquisition, disposition or run-off activities | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 3,646 | |
Acquisition, disposition or run-off activities | BBB+ equivalent and higher current ratings | Lincoln National Life and Lincoln Life & Annuity of New York | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 2,619 | |
Acquisition, disposition or run-off activities | BBB+ equivalent and higher current ratings | Empower Annuity Insurance Company | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 128 | |
Acquisition, disposition or run-off activities | BBB+ equivalent and higher current ratings | Prudential Insurance Company of America | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 351 | |
Acquisition, disposition or run-off activities | BBB+ equivalent and higher current ratings | Life Insurance Company of North America | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 334 | |
Acquisition, disposition or run-off activities | BBB+ equivalent and higher current ratings | Other | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 204 | |
Acquisition, disposition or run-off activities | Not rated | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 10 | |
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 before market risk benefits, including assets held for sale | 518 | |
Acquisition, disposition or run-off activities | Fair value of collateral contractually required to meet or exceed carrying value of recoverable | BBB+ equivalent and higher current ratings | Lincoln National Life and Lincoln Life & Annuity of New York | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 0 | |
Acquisition, disposition or run-off activities | Fair value of collateral contractually required to meet or exceed carrying value of recoverable | BBB+ equivalent and higher current ratings | Empower Annuity Insurance Company | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 0 | |
Acquisition, disposition or run-off activities | Fair value of collateral contractually required to meet or exceed carrying value of recoverable | BBB+ equivalent and higher current ratings | Prudential Insurance Company of America | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 351 | |
Acquisition, disposition or run-off activities | Fair value of collateral contractually required to meet or exceed carrying value of recoverable | BBB+ equivalent and higher current ratings | Life Insurance Company of North America | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 0 | |
Acquisition, disposition or run-off activities | Fair value of collateral contractually required to meet or exceed carrying value of recoverable | BBB+ equivalent and higher current ratings | Other | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 167 | |
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 before market risk benefits, including assets held for sale | 0 | |
Acquisition, disposition or run-off activities | Collateral provisions exist that may mitigate risk of credit loss | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 2,982 | |
Acquisition, disposition or run-off activities | Collateral provisions exist that may mitigate risk of credit loss | BBB+ equivalent and higher current ratings | Lincoln National Life and Lincoln Life & Annuity of New York | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 2,619 | |
Acquisition, disposition or run-off activities | Collateral provisions exist that may mitigate risk of credit loss | BBB+ equivalent and higher current ratings | Empower Annuity Insurance Company | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 0 | |
Acquisition, disposition or run-off activities | Collateral provisions exist that may mitigate risk of credit loss | BBB+ equivalent and higher current ratings | Prudential Insurance Company of America | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 0 | |
Acquisition, disposition or run-off activities | Collateral provisions exist that may mitigate risk of credit loss | BBB+ equivalent and higher current ratings | Life Insurance Company of North America | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 334 | |
Acquisition, disposition or run-off activities | Collateral provisions exist that may mitigate risk of credit loss | BBB+ equivalent and higher current ratings | Other | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 23 | |
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 before market risk benefits, including assets held for sale | 6 | |
Acquisition, disposition or run-off activities | No collateral | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 146 | |
Acquisition, disposition or run-off activities | No collateral | BBB+ equivalent and higher current ratings | Lincoln National Life and Lincoln Life & Annuity of New York | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 0 | |
Acquisition, disposition or run-off activities | No collateral | BBB+ equivalent and higher current ratings | Empower Annuity Insurance Company | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 128 | |
Acquisition, disposition or run-off activities | No collateral | BBB+ equivalent and higher current ratings | Prudential Insurance Company of America | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 0 | |
Acquisition, disposition or run-off activities | No collateral | BBB+ equivalent and higher current ratings | Life Insurance Company of North America | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 0 | |
Acquisition, disposition or run-off activities | No collateral | BBB+ equivalent and higher current ratings | Other | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | 14 | |
Acquisition, disposition or run-off activities | No collateral | Not rated | | |
Ceded Credit Risk [Line Items] | | |
Reinsurance recoverables before market risk benefits, including assets held for sale | $ 4 | |