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Employee Share-Based Incentive Compensation Plans (Tables) | 3 Months Ended
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Mar. 31, 2024
Share-Based Payment Arrangement [Abstract] |
Summary of performance shares outstanding and accrued expense for performance shares awarded under the WTM Incentive Plan | The following table presents the performance share activity for the three months ended March 31, 2024 and 2023 for performance shares granted under the WTM Incentive Plan:
|  |  |  | Three Months Ended March 31,
|  |  |  |  |  | 2024 |  | 2023
$ in Millions |  |  |  |  |  |  |  |  |  | Target Performance Shares Outstanding |  | Accrued Expense |  | Target Performance Shares Outstanding |  | Accrued Expense
Beginning of period |  |  |  |  |  |  |  |  |  | 37,031 |  |  | $ | 69.4 |  |  | 39,449 |  |  | $ | 67.5 |
Shares paid (1) |  |  |  |  |  |  |  |  |  | (13,475) |  |  | (44.9) |  |  | (13,350) |  |  | (40.8) |
New grants |  |  |  |  |  |  |  |  |  | 10,405 |  |  | — |  |  | 10,895 |  |  | — |
Forfeitures and cancellations (2) |  |  |  |  |  |  |  |  |  | 46 |  |  | .3 |  |  | 37 |  |  | .4 |
Expense recognized |  |  |  |  |  |  |  |  |  | — |  |  | 19.4 |  |  | — |  |  | 9.3 |
End of period |  |  |  |  |  |  |  |  |  | 34,007 |  |  | $ | 44.2 |  |  | 37,031 |  |  | $ | 36.4 |
(1) WTM performance share payments for the 2021-2023 performance cycle were made in March 2024 at 188% of target. WTM performance share payments for the 2020-2022 performance cycle were made in March 2023 at 200% of target. (2) Amounts include changes in assumed forfeitures, as required under GAAP.
Share-based compensation, performance shares award outstanding activity | The following table presents performance shares outstanding and accrued expense for performance shares awarded under the WTM Incentive Plan as of March 31, 2024 for each performance cycle:
|  | March 31, 2024
$ in Millions |  | Target Performance Shares Outstanding |  | Accrued Expense
Performance cycle: |  |  |  |
2022 – 2024 |  | 13,225 |  |  | $ | 35.0 |
2023 – 2025 |  | 10,895 |  |  | 9.4 |
2024 – 2026 |  | 10,405 |  |  | .6 |
Sub-total |  | 34,525 |  |  | 45.0 |
Assumed forfeitures |  | (518) |  |  | (.8) |
Total |  | 34,007 |  |  | $ | 44.2 |
Unrecognized compensation cost for restricted share awards | The following table presents the unrecognized compensation cost associated with the outstanding restricted share awards under the WTM Incentive Plan for the three months ended March 31, 2024 and 2023:
|  |  |  | Three Months Ended March 31,
|  |  |  |  |  | 2024 |  | 2023
$ in Millions |  |  |  |  |  |  |  |  |  | Restricted Shares |  | Unamortized Issue Date Fair Value |  | Restricted Shares |  | Unamortized Issue Date Fair Value
Non-vested, |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning of period |  |  |  |  |  |  |  |  |  | 37,595 |  |  | $ | 16.2 |  |  | 38,350 |  |  | $ | 15.5 |
Issued |  |  |  |  |  |  |  |  |  | 10,405 |  |  | 18.3 |  |  | 10,895 |  |  | 16.0 |
Vested |  |  |  |  |  |  |  |  |  | (13,475) |  |  | — |  |  | (11,650) |  |  | — |
Forfeited |  |  |  |  |  |  |  |  |  | — |  |  | — |  |  | — |  |  | — |
Expense recognized |  |  |  |  |  |  |  |  |  | — |  |  | (3.2) |  |  | — |  |  | (3.2) |
End of period |  |  |  |  |  |  |  |  |  | 34,525 |  |  | $ | 31.3 |  |  | 37,595 |  |  | $ | 28.3 |

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- Definition Tabular disclosure of the changes in outstanding nonvested restricted stock shares. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Subparagraph (c) -Paragraph 2 -SubTopic 10 -Topic 718 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480429/718-10-50-2 + Details
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- Definition Tabular disclosure of the number and weighted-average grant date fair value for outstanding performance shares. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Subparagraph (c) -Paragraph 2 -SubTopic 10 -Topic 718 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480429/718-10-50-2 + Details
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