Clearwater Paper Corp

NOTE 5 Goodwill and Intangible Assets

Changes in the carrying amounts of goodwill and intangible assets allocated to each segment were as follows:

For all periods presented in the table above, the Consumer Products segment had no goodwill or intangible assets with a net book value. The above balances are included in "Other assets, net" on the Consolidated Balance Sheets.

As of December 31, 2023, intangible assets consisted of $6.4 million customer relationships. As of December 31, 2022, intangible assets consisted of $8.6 million of customer relationships. Outstanding definite-lived intangible assets are amortized over their useful lives of 10 years.

We annually evaluate goodwill for possible impairment as of November 1 with additional interim evaluation performed when management believes that it is more likely than not that events or circumstances have occurred that would result in the impairment of a reporting unit’s goodwill. We evaluate our intangible assets for impairment when events or changes in circumstances indicate that the carrying value may not be recoverable.

The gross book value and accumulated amortization of definite lived intangible assets at December 31, 2023 was $34.9 million and $28.4 million. The gross book value and accumulated amortization of definite lived intangible assets at December 31, 2022 was $34.9 million and $26.3 million.

As of December 31, 2023, estimated future amortization expense related to intangible assets is as follows: