XML 48 R37.htm IDEA: XBRL DOCUMENT
v3.24.1.u1

Noncontrolling Interests (Tables) | 3 Months Ended
--- | ---
Mar. 31, 2024
Noncontrolling Interest [Abstract] |
Non-controlling interests | The following table presents the balance of noncontrolling interests included in White Mountains’s total equity and the related percentage of each consolidated entity’s total equity owned by noncontrolling shareholders as of March 31, 2024 and December 31, 2023:
|  | March 31, 2024 |  | December 31, 2023 |
$ in Millions |  | Noncontrolling Percentage (1) |  | Noncontrolling Equity |  | Noncontrolling Percentage (1) |  | Noncontrolling Equity |
Noncontrolling interests, excluding BAM |  |  |  |  |  |  |  |  |
Ark |  | 28.0 | % |  | $ | 334.7 |  | (2) | 28.0 | % |  | $ | 336.9 |  | (2)
HG Global |  | 3.1 | % |  | (.4) |  |  | 3.1 | % |  | .8 |  |
Kudu |  | 10.6 | % |  | 114.4 |  |  | 10.5 | % |  | 113.8 |  |
Bamboo |  | 27.2 | % |  | 111.3 |  |  | — | % |  | — |  |
Other |  | various |  | 9.3 |  |  | various |  | 9.4 |  |
Total, excluding BAM |  |  |  | 569.3 |  |  |  |  | 460.9 |  |
BAM |  | 100.0 | % |  | (149.1) |  |  | 100.0 | % |  | (139.8) |  |
Total noncontrolling interests |  |  |  | $ | 420.2 |  |  |  |  | $ | 321.1 |  |
(1) The noncontrolling percentage represents the basic ownership interests held by noncontrolling shareholders with the exception of HG Global, for which the noncontrolling percentage represents the preferred share ownership held by noncontrolling shareholders. (2) As of March 31, 2024 and December 31, 2023, Ark’s noncontrolling equity includes $17.9 and $21.0 related to management’s equity incentives.

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

X
- Definition Non-controlling Interests [Table Text Block] + References No definition available. + Details
Name: | wtm_NoncontrollingInterestsTableTextBlock
Namespace Prefix: | wtm_
Data Type: | dtr-types1:textBlockItemType
Balance Type: | na
Period Type: | duration