XML 44 R33.htm IDEA: XBRL DOCUMENT
v3.20.2

Employee Share-Based Incentive Compensation Plans (Tables) | 9 Months Ended
--- | ---
Sep. 30, 2020
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 and nine months ended September 30, 2020 and 2019 for performance shares granted under the WTM Incentive Plan:
|  | Three Months Ended September 30, |  | Nine Months Ended September 30,
|  | 2020 |  | 2019 |  | 2020 |  | 2019
Millions, except share amounts |  | Target Performance Shares Outstanding |  | Accrued Expense |  | Target Performance Shares Outstanding |  | Accrued Expense |  | Target Performance Shares Outstanding |  | Accrued Expense |  | Target Performance Shares Outstanding |  | Accrued Expense
Beginning of period |  | 42,458 |  |  | $ | 15.8 |  |  | 42,473 |  |  | $ | 30.8 |  |  | 42,473 |  |  | $ | 43.7 |  |  | 40,616 |  |  | $ | 31.7 |
Shares paid (1) |  | — |  |  | — |  |  | — |  |  | — |  |  | (14,070 | ) |  | (27.7 | ) |  | (13,715 | ) |  | (18.1 | )
New grants |  | — |  |  | — |  |  | — |  |  | — |  |  | 14,055 |  |  | — |  |  | 15,600 |  |  | — |
Forfeitures and cancellations(2) |  | — |  |  | (.3 | ) |  | — |  |  | — |  |  | — |  |  | .1 |  |  | (28 | ) |  | — |
Expense recognized |  | — |  |  | 13.6 |  |  | — |  |  | 5.6 |  |  | — |  |  | 13.0 |  |  | — |  |  | 22.8 |
End of period |  | 42,458 |  |  | $ | 29.1 |  |  | 42,473 |  |  | $ | 36.4 |  |  | 42,458 |  |  | $ | 29.1 |  |  | 42,473 |  |  | $ | 36.4 |
(1) WTM performance share payments in 2020 for the 2017-2019 performance cycle, which were paid in cash in March 2020, ranged from 174% to 180% of target. WTM performance share payments in 2019 for the 2016-2018 performance cycle, which were paid in cash in March 2019, ranged from 139% to 166% 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 September 30, 2020 for each performance cycle:
|  | Nine Months Ended September 30, 2020
Millions, except share amounts |  | Target Performance Shares Outstanding |  | Accrued Expense
Performance cycle: |  |  |  |  |  |
2018 – 2020 |  | 13,450 |  |  | $ | 15.4 |
2019 – 2021 |  | 15,600 |  |  | 10.6 |
2020 – 2022 |  | 14,055 |  |  | 3.6 |
Sub-total |  | 43,105 |  |  | 29.6 |
Assumed forfeitures |  | (647 | ) |  | (.5 | )
September 30, 2020 |  | 42,458 |  |  | $ | 29.1 |
Summary of restricted shares activity | The following table presents the unrecognized compensation cost associated with the outstanding restricted share awards for the three and nine months ended September 30, 2020 and 2019:
|  | Three Months Ended September 30, |  | Nine Months Ended September 30,
|  | 2020 |  | 2019 |  | 2020 |  | 2019
Millions, except share amounts |  | Restricted Shares |  | Unamortized Issue Date Fair Value |  | Restricted Shares |  | Unamortized Issue Date Fair Value |  | Restricted Shares |  | Unamortized Issue Date Fair Value |  | Restricted Shares |  | Unamortized Issue Date Fair Value
Non-vested, |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning of period |  | 43,105 |  |  | $ | 23.0 |  |  | 43,395 |  |  | $ | 21.9 |  |  | 43,395 |  |  | $ | 16.7 |  |  | 41,510 |  |  | $ | 12.5 |
Issued |  | — |  |  | — |  |  | — |  |  | — |  |  | 14,055 |  |  | 15.1 |  |  | 15,600 |  |  | 14.5 |
Vested |  | — |  |  | — |  |  | — |  |  | — |  |  | (14,345 | ) |  | — |  |  | (13,715 | ) |  | — |
Forfeited |  | — |  |  | — |  |  | — |  |  | — |  |  | — |  |  | — |  |  | — |  |  | — |
Expense recognized |  | — |  |  | (3.6 | ) |  | — |  |  | (2.6 | ) |  | — |  |  | (12.4 | ) |  | — |  |  | (7.7 | )
End of period |  | 43,105 |  |  | $ | 19.4 |  |  | 43,395 |  |  | $ | 19.3 |  |  | 43,105 |  |  | $ | 19.4 |  |  | 43,395 |  |  | $ | 19.3 |

X
- References No definition available. + Details
Name: | us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- 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 -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationPerformanceSharesAwardOutstandingActivityTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the changes in nonvested performance shares outstanding and the amount accrued for performance shares. + References No definition available. + Details
Name: | wtm_ScheduleOfNonvestedPerformanceShareActivityTableTextBlock
Namespace Prefix: | wtm_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the changes in nonvested restricted shares and the unamortized grant date fair value. + References No definition available. + Details
Name: | wtm_ScheduleofNonvestedRestrictedShareActivityTableTextBlock
Namespace Prefix: | wtm_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration