5.    Goodwill and Intangible Assets

The following is a summary of changes to the goodwill carrying value from December 31, 2023 to September 30, 2024:

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The following table summarizes the Company’s intangible assets and related accumulated amortization:

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Amortization expense related to intangible assets for the three months ended September 30, 2024 and September 30, 2023 was $7.2 million and $7.4 million, respectively. Amortization expense related to intangible assets amounted to $21.6 million and $20.0 million for the nine months ended September 30, 2024 and September 30, 2023, respectively.

Estimated future expected amortization expense of intangible assets as of September 30, 2024 is as follows:

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The weighted-average remaining useful life by major asset classes as of September 30, 2024 is as follows:

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There were no impairments of Goodwill or Intangible assets identified during the nine months ended September 30, 2024 and September 30, 2023.