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Fair value measurements (Financial Instruments Measured At Fair Value On Recurring Basis) (Details) - USD ($) $ in Millions | Sep. 30, 2022 | Dec. 31, 2021
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Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | $ 83,741 |  | $ 93,108 |
Equity securities, at fair value |  | 844 |  | 4,782 |
Short-term investments, at fair value (amortized cost – $4,536 and $3,147) |  | 4,534 |  | 3,146 |
Other investments, at fair value |  | 13,645 |  | 11,169 |
Securities lending collateral |  | 1,626 |  | 1,831 |
Investment Funds Limited Partnerships Partially Owned Investment Companies Fair Value |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Other investments, at fair value |  | 12,392 |  | 10,108 |
Policy Loans |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Other investments, at fair value |  | 316 |  | 243 |
Other Investments |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Other investments, at fair value |  | 50 |  | 51 |
U.S. Treasury / Agency |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 2,556 |  | 2,214 |
Non-U.S. |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 24,183 |  | 25,829 |
Corporate and asset-backed securities |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 36,380 |  | 39,063 |
Mortgage-backed securities |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 16,235 |  | 20,489 |
Municipal |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 4,387 |  | 5,513 |
Level 1 | Fair Value, Recurring |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 2,032 |  | 1,680 |
Equity securities, at fair value |  | 761 |  | 4,705 |
Short-term investments, at fair value (amortized cost – $4,536 and $3,147) |  | 2,782 |  | 1,744 |
Other investments, at fair value |  | 506 | [1] | 286 | [2]
Securities lending collateral |  | 0 |  | 0 |
Investment derivative instruments, assets |  | 129 |  | 58 |
Other Derivative Instruments Fair Value |  | 109 |  |  |
Derivative Instruments in Hedges, at Fair Value |  | 0 |  |  |
Separate Account Asset |  | 4,810 |  | 5,461 |
Total assets measured at fair value |  | 11,129 | [1] | 13,934 | [2]
Investment derivative instruments, liabilities |  | 306 |  | 166 |
Other derivative instruments, liability |  |  |  | 16 |
Derivative Instruments in Hedges, Liabilities, at Fair Value |  | 0 |  |  |
Liabilities Related to Investment Contracts, Fair Value Disclosure |  | 306 |  | 182 |
Level 1 | Fair Value, Recurring | GLB |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross |  | 0 | [3] | 0 | [4]
Level 1 | U.S. Treasury / Agency | Fair Value, Recurring |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 2,032 |  | 1,680 |
Level 1 | Non-U.S. | Fair Value, Recurring |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 0 |  | 0 |
Level 1 | Corporate and asset-backed securities | Fair Value, Recurring |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 0 |  | 0 |
Level 1 | Mortgage-backed securities | Fair Value, Recurring |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 0 |  | 0 |
Level 1 | Municipal | Fair Value, Recurring |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 0 |  | 0 |
Level 2 | Fair Value, Recurring |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 78,888 |  | 88,720 |
Equity securities, at fair value |  | 0 |  | 0 |
Short-term investments, at fair value (amortized cost – $4,536 and $3,147) |  | 1,749 |  | 1,395 |
Other investments, at fair value |  | 381 | [1] | 481 | [2]
Securities lending collateral |  | 1,626 |  | 1,831 |
Investment derivative instruments, assets |  | 0 |  | 0 |
Other Derivative Instruments Fair Value |  | 0 |  |  |
Derivative Instruments in Hedges, at Fair Value |  | 71 |  |  |
Separate Account Asset |  | 81 |  | 99 |
Total assets measured at fair value |  | 82,796 | [1] | 92,526 | [2]
Investment derivative instruments, liabilities |  | 0 |  | 0 |
Other derivative instruments, liability |  |  |  | 0 |
Derivative Instruments in Hedges, Liabilities, at Fair Value |  | 101 |  |  |
Liabilities Related to Investment Contracts, Fair Value Disclosure |  | 101 |  | 0 |
Level 2 | Fair Value, Recurring | GLB |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross |  | 0 | [3] | 0 | [4]
Level 2 | U.S. Treasury / Agency | Fair Value, Recurring |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 524 |  | 534 |
Level 2 | Non-U.S. | Fair Value, Recurring |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 23,677 |  | 25,196 |
Level 2 | Corporate and asset-backed securities | Fair Value, Recurring |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 34,084 |  | 37,014 |
Level 2 | Mortgage-backed securities | Fair Value, Recurring |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 16,216 |  | 20,463 |
Level 2 | Municipal | Fair Value, Recurring |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 4,387 |  | 5,513 |
Level 3 | Fair Value, Recurring |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 2,821 |  | 2,708 |
Equity securities, at fair value |  | 83 |  | 77 |
Short-term investments, at fair value (amortized cost – $4,536 and $3,147) |  | 3 |  | 7 |
Other investments, at fair value |  | 0 | [1] | 0 | [2]
Securities lending collateral |  | 0 |  | 0 |
Investment derivative instruments, assets |  | 0 |  | 0 |
Other Derivative Instruments Fair Value |  | 0 |  |  |
Derivative Instruments in Hedges, at Fair Value |  | 0 |  |  |
Separate Account Asset |  | 0 |  | 0 |
Total assets measured at fair value |  | 2,907 | [1] | 2,792 | [2]
Investment derivative instruments, liabilities |  | 0 |  | 0 |
Other derivative instruments, liability |  |  |  | 0 |
Derivative Instruments in Hedges, Liabilities, at Fair Value |  | 0 |  |  |
Liabilities Related to Investment Contracts, Fair Value Disclosure |  | 784 |  | 745 |
Level 3 | Fair Value, Recurring | GLB |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross | [5] | 784 |  | 745 | [4]
Level 3 | U.S. Treasury / Agency | Fair Value, Recurring |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 0 |  | 0 |
Level 3 | Non-U.S. | Fair Value, Recurring |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 506 |  | 633 |
Level 3 | Corporate and asset-backed securities | Fair Value, Recurring |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 2,296 |  | 2,049 |
Level 3 | Mortgage-backed securities | Fair Value, Recurring |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 19 |  | 26 |
Level 3 | Municipal | Fair Value, Recurring |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 0 |  | 0 |
Total Level 1, Level 2, and Level 3 | Fair Value, Recurring |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 83,741 |  | 93,108 |
Equity securities, at fair value |  | 844 |  | 4,782 |
Short-term investments, at fair value (amortized cost – $4,536 and $3,147) |  | 4,534 |  | 3,146 |
Other investments, at fair value |  | 887 | [1] | 767 | [2]
Securities lending collateral |  | 1,626 |  | 1,831 |
Investment derivative instruments, assets |  | 129 |  | 58 |
Other Derivative Instruments Fair Value |  | 109 |  |  |
Derivative Instruments in Hedges, at Fair Value |  | 71 |  |  |
Separate Account Asset |  | 4,891 |  | 5,560 |
Total assets measured at fair value |  | 96,832 | [1] | 109,252 | [2]
Investment derivative instruments, liabilities |  | 306 |  | 166 |
Other derivative instruments, liability |  |  |  | 16 |
Derivative Instruments in Hedges, Liabilities, at Fair Value |  | 101 |  |  |
Liabilities Related to Investment Contracts, Fair Value Disclosure |  | 1,191 |  | 927 |
Total Level 1, Level 2, and Level 3 | Fair Value, Recurring | GLB |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross |  | 784 | [3] | 745 | [4]
Total Level 1, Level 2, and Level 3 | U.S. Treasury / Agency | Fair Value, Recurring |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 2,556 |  | 2,214 |
Total Level 1, Level 2, and Level 3 | Non-U.S. | Fair Value, Recurring |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 24,183 |  | 25,829 |
Total Level 1, Level 2, and Level 3 | Corporate and asset-backed securities | Fair Value, Recurring |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 36,380 |  | 39,063 |
Total Level 1, Level 2, and Level 3 | Mortgage-backed securities | Fair Value, Recurring |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | 16,235 |  | 20,489 |
Total Level 1, Level 2, and Level 3 | Municipal | Fair Value, Recurring |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |  |  |  |
Available for sale, Fair Value |  | $ 4,387 |  | $ 5,513 |
[1] | Excluded from the table above are partially-owned investments, investment funds, and limited partnerships of $12,392 million, policy loans of $316 million, and other investments of $50 million at September 30, 2022 measured using NAV as a practical expedient.
[2] | Excluded from the table above are partially-owned investments, investment funds, and limited partnerships of $10,108 million, policy loans of $243 million and other investments of $51 million at December 31, 2021, measured using NAV as a practical expedient.
[3] | Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value.
[4] | Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value.
[5] | The weighted-average lapse and annuitization rates are determined by weighting each treaty's rates by the GLB contracts fair value.

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