XML 282 R38.htm IDEA: XBRL DOCUMENT
v3.21.2

Leases (Tables) | 6 Months Ended
--- | ---
Jun. 30, 2021
Leases [Abstract] |
Summary of Lease Expense | The following table summarizes net lease expense recognized in White Mountains’s consolidated statement of operations for the three and six months ended June 30, 2021 and 2020:
Millions |  | Three Months Ended June 30, |  | Six Months Ended June 30,
Lease Cost |  | 2021 |  | 2020 |  | 2021 |  | 2020
Lease cost |  | $ | 2.6 |  |  | $ | 2.1 |  |  | $ | 4.5 |  |  | $ | 4.1 |
Less: sublease income |  | .1 |  |  | .1 |  |  | .2 |  |  | .2 |
Net lease cost |  | $ | 2.5 |  |  | $ | 2.0 |  |  | $ | 4.3 |  |  | $ | 3.9 |
Schedule of Future Maturities of Operating Lease Liabilities, Lessee | The following table presents the contractual maturities of the lease liabilities associated with White Mountains’s operating lease agreements as of June 30, 2021:
Millions |  | As of June 30, 2021
Remainder of 2021 |  | $ | 4.0 |
2022 |  | 10.8 |
2023 |  | 9.8 |
2024 |  | 8.5 |
2025 |  | 6.7 |
Thereafter |  | 16.3 |
Total undiscounted lease payments |  | 56.1 |
Less: present value adjustment |  | 8.8 |
Operating lease liability |  | $ | 47.3 |
Schedule of Right-of-Use Assets and Lease Liabilities | The following tables present lease related assets and liabilities by reportable segment as of June 30, 2021 and December 31, 2020:
|  | As of June 30, 2021
Millions |  | HG/BAM |  | Ark |  | NSM |  | Kudu |  | Other Operations |  | Total |  | Weighted Average Incremental Borrowing Rate (1)
ROU lease asset |  | $ | 8.5 |  |  | $ | 7.1 |  |  | $ | 14.0 |  |  | $ | 6.9 |  |  | $ | 7.8 |  |  | $ | 44.3 |  |  | 5.0%
Lease liability |  | $ | 9.2 |  |  | $ | 7.1 |  |  | $ | 15.3 |  |  | $ | 7.1 |  |  | $ | 8.6 |  |  | $ | 47.3 |  |
(1) The present value of the remaining lease payments was determined by discounting the lease payments using the incremental borrowing rate.
|  | As of December 31, 2020
Millions |  | HG/BAM |  | NSM |  | Kudu |  | Other Operations |  | Total |  | Weighted Average Incremental Borrowing Rate (1)
ROU lease asset |  | $ | 10.1 |  |  | $ | 17.1 |  |  | $ | 2.0 |  |  | $ | 8.4 |  |  | $ | 37.6 |  |  | 4.6%
Lease liability |  | $ | 10.1 |  |  | $ | 17.1 |  |  | $ | 2.0 |  |  | $ | 9.1 |  |  | $ | 38.3 |  |
(1) The present value of the remaining lease payments was determined by discounting the lease payments using the incremental borrowing rate.

X
- Definition Tabular disclosure of lessee's lease cost. Includes, but is not limited to, interest expense for finance lease, amortization of right-of-use asset for finance lease, operating lease cost, short-term lease cost, variable lease cost and sublease income. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=121609121&loc=SL77918686-209980 + Details
Name: | us-gaap_LeaseCostTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

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

X
- Definition Tabular disclosure of undiscounted cash flows of lessee's operating lease liability. Includes, but is not limited to, reconciliation of undiscounted cash flows to operating lease liability recognized in statement of financial position. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=121609121&loc=SL77918701-209980 + Details
Name: | us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Schedule of Right-of-Use Assets and Lease Liabilities [Table Text Block] + References No definition available. + Details
Name: | wtm_ScheduleofRightofUseAssetsandLeaseLiabilitiesTableTextBlock
Namespace Prefix: | wtm_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration