XML 54 R37.htm IDEA: XBRL DOCUMENT
v3.25.4

Leases (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2025
Leases [Abstract] |
Components of Lease Expense | The components of lease expense were as follows:
(in millions) |  | Twelve Months Ended December 31 |  |  | Twelve Months Ended December 31 |  |  | Twelve Months Ended December 31 |
|  | 2025 |  |  | 2024 |  |  | 2023 |
Operating lease cost |  |  | 18.2 |  |  |  | 17.1 |  |  |  | 17.9 |
Short-term lease cost |  |  | 7.7 |  |  |  | 8.7 |  |  |  | 8.1 |
Total lease cost |  | $ | 25.9 |  |  | $ | 25.8 |  |  | $ | 26.0 |
Supplemental Cash Flow Information Related to Leases | Supplemental cash flow information related to leases is as follows:
(in millions) |  | Twelve Months Ended December 31 |  |  | Twelve Months Ended December 31 |  |  | Twelve Months Ended December 31 |
|  | 2025 |  |  | 2024 |  |  | 2023 |
Cash paid for amounts included in the measurement of lease liabilities: |  |  |  |  |  |  |  |  |
Operating cash flows from operating leases |  | $ | 25.9 |  |  | $ | 25.9 |  |  | $ | 26.1 |
Right-of-use assets obtained in exchange for new lease obligations: |  |  |  |  |  |  |  |  |
Operating leases |  | $ | 15.1 |  |  | $ | 14.0 |  |  | $ | 11.0 |
Supplemental Balance Sheet Information Related to Leases | Supplemental balance sheet information related to leases is as follows:
(in millions except lease term and discount rate) |  | December 31, 2025 |  |  | December 31, 2024 |
Operating leases: |  |  |  |  |  |
Operating lease right-of-use assets |  | $ | 52.7 |  |  | $ | 44.8 |
Current portion of operating lease liabilities |  | $ | 15.9 |  |  | $ | 13.9 |
Operating lease liabilities, net of current portion |  |  | 36.8 |  |  |  | 31.0 |
Total operating lease liabilities |  | $ | 52.7 |  |  | $ | 44.9 |
Weighted average remaining lease term: |  |  |  |  |  |
Operating leases |  | 6.3 years |  |  | 5.6 years |
Weighted average discount rate: |  |  |  |  |  |
Operating leases |  |  | 4.1 | % |  |  | 3.8 | %
Maturities of Lease Liabilities | Maturities of lease liabilities were as follows as at December 31, 2025:
(in millions) |  | Operating Leases |
Within one year |  | $ | 16.3 |
Year two |  |  | 10.0 |
Year three |  |  | 8.1 |
Year four |  |  | 6.4 |
Year five |  |  | 4.9 |
Thereafter |  |  | 15.3 |
Total lease payments |  |  | 61.0 |
Less imputed interest |  |  | (8.3 | )
Total |  | $ | 52.7 |
As of December 31, 2025, additional operating and finance leases that have not yet commenced are $0.7 million. Maturities of lease liabilities were as follows as at December 31, 2024:
(in millions) |  | Operating Leases |
Within one year |  | $ | 14.3 |
Year two |  |  | 9.8 |
Year three |  |  | 5.7 |
Year four |  |  | 5.1 |
Year five |  |  | 3.9 |
Thereafter |  |  | 11.7 |
Total lease payments |  |  | 50.5 |
Less imputed interest |  |  | (5.6 | )
Total |  | $ | 44.9 |

X
- Definition Schedule of maturities of operating and finance leases liabilities. + References No definition available. + Details
Name: | iosp_ScheduleOfMaturitiesOfOperatingAndFinanceLeasesLiabilitiesTableTextBlock
Namespace Prefix: | iosp_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Schedule of supplemental cash flow information related to leases. + References No definition available. + Details
Name: | iosp_ScheduleOfSupplementalCashFlowInformationRelatedToLeasesTableTextBlock
Namespace Prefix: | iosp_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Supplemental balance sheet information related to leases Table text Block + References No definition available. + Details
Name: | iosp_SupplementalBalanceSheetInformationRelatedToLeasesTableTextBlock
Namespace Prefix: | iosp_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

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 -Topic 842 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147478964/842-20-50-4 + Details
Name: | us-gaap_LeaseCostTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types: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