13. GOODWILL AND INTANGIBLE ASSETS
    
Goodwill Changes in the carrying amount of goodwill are as follows:

Segment
(in thousands)ElectricalSafety & InfrastructureTotal
Balance as of September 30, 2023$258,427 $52,679 $311,106 
Exchange rate effects2,857 37 2,894 
Balance as of September 30, 2024$261,284 $52,716 $314,000 
Impairment— (18,885)(18,885)
Divestiture(755)— (755)
Exchange rate effects314 (189)125 
Balance as of September 30, 2025$260,843 $33,642 $294,485 

Goodwill balances include $5,645 and $61,885 of accumulated impairment losses within the Electrical and Safety & Infrastructure segments, respectively, as of September 30, 2025. As a result of the sale of Northwest Polymers, the Company recognized divested allocated goodwill of $755 and, as a result of the Company’s annual goodwill testing, it was determined that the goodwill of the Mechanical reporting unit was impaired as the reporting unit’s book value exceeded its fair value. The Company recorded a goodwill impairment on the Mechanical reporting unit of $18,885. No goodwill impairments were recognized in fiscal 2024.

Intangible Assets — The following table provides the gross carrying value, accumulated amortization, and net carrying value for each major class of intangible assets:
  September 30, 2025September 30, 2024
(in thousands)Weighted Average Useful Life (Years)Gross Carrying ValueAccumulated AmortizationNet Carrying ValueGross Carrying ValueAccumulated AmortizationNet Carrying Value
Amortizable Intangible Assets:
Customer relationships10$401,771 $(338,201)$63,570 $600,317 $(371,600)$228,717 
Other825,205 (20,797)4,408 43,968 (25,067)18,901 
Total426,976 (358,998)67,978 644,285 (396,667)247,618 
Indefinite-lived Intangible Assets:
Trade names92,780 — 92,780 92,813 — 92,813 
Total$519,756 $(358,998)$160,758 $737,098 $(396,667)$340,431 

During fiscal 2025, the Company recorded non-cash impairment charges totaling $129,907, primarily related to customer relationships. Refer to Note 14, “Fair Value Measurements” for further discussion of the Company’s impairment review. As a result of the asset impairment charges, the book basis of the HDPE intangible assets was adjusted to the new fair value. This resulted in the elimination of previously accumulated amortization of $77,927, as well as an equivalent reduction in gross intangibles.

Other intangible assets consist of definite-lived trade names, technology, non-compete agreements and backlogs. Included in the table above are the effects of changes in exchange rates, which were not material for the fiscal year ended September 30, 2025. Amortization expense for the fiscal years ended September 30, 2025, September 30, 2024 and September 30, 2023 was $41,924, $55,511 and $57,804, respectively.
Expected amortization expense for intangible assets over the next five years and thereafter is as follows (in thousands):
2026$24,945 
202723,949 
20289,035 
20292,924 
20302,924 
2031 and thereafter4,202 
Actual amounts of amortization may differ from estimated amounts due to additional intangible asset acquisitions, changes in estimated useful lives, impairment of intangible assets, and other events. As a result of the HDPE impairments described in Note 15, “Fair Value Measurements”, the estimated remaining weighted average useful life for the HDPE business’s customer relationships intangibles has been reduced from 7 years to 3 years.

Historical Timeline

Fiscal YearFiled
2025Nov 26, 2025Showing above
2024Nov 21, 2024
2023Nov 17, 2023
2022Nov 18, 2022
2021Nov 18, 2021
2020Nov 19, 2020
2019Nov 22, 2019
2018Nov 28, 2018
2017Nov 29, 2017
2016Nov 29, 2016

About Goodwill & Intangibles Disclosures

Goodwill and intangible asset disclosures reveal the premium paid in acquisitions and how management assesses whether that premium retains its value. Since goodwill is no longer amortized under US GAAP, the annual impairment test is the only mechanism that adjusts carrying values downward — making the assumptions behind that test critically important for investors.

Key signals: a history of goodwill impairments suggests management consistently overpays for acquisitions. Watch the gap between reporting unit fair value and carrying amount — when fair value exceeds carrying amount by less than 10-20%, a small decline in business performance could trigger a write-down. For finite-lived intangibles, examine useful life assumptions across customer relationships, technology, and trade names; aggressive estimates inflate near-term earnings. Compare total intangibles-to-total-assets ratios against peers to assess acquisition dependency. Rising goodwill as a percentage of equity can signal balance sheet fragility.