(6) Goodwill and Other Intangible Assets

Goodwill and Indefinite Lived Intangible Assets

Changes in the carrying amount of goodwill are as follows:

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As presented in the accompanying consolidated balance sheets, trademarks are the other significant indefinite lived intangible asset. See the disclosure below for information related to the 2020 and 2019 impairments of the Company’s trademarks. Other fluctuations in the trademark balance from the prior year were due to the change in foreign exchange rates.

Intangible Assets subject to amortization

Intangible assets subject to amortization are comprised of the following:

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Amortization expense was $122 million, $136 million and $139 million for the years ended December 31, 2021, 2020 and 2019, respectively.

Intangible assets are generally amortized on a straight-line basis. The estimated future amortization expense for the next five years related to intangible assets with definite lives as of December 31, 2021 is as follows (amounts in millions):

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Impairments

Due to the impact of COVID-19 on Tripadvisor’s operating results, and a sustained decline in Tripadvisor’s stock price, impairments of $250 million of trademarks and $279 million of goodwill were recorded during the year ended December 31, 2020, respectively, related to the Hotels, Media & Platform reporting unit. The fair value of the trademarks was determined using the relief from royalty method. The fair value of the reporting unit was determined using a combination of market multiples (market approach) and discounted cash flow (income approach) calculations (Level 3). 

Due to deteriorations in revenue, impairment losses of $288 million were recorded during the year ended December 31, 2019 related to trademarks.  The trademarks were related to the hotels, media & platform reporting unit in 2019.  The fair value of the trademarks was determined using the relief from royalty method.

As of December 31, 2021, accumulated goodwill impairment losses for Tripadvisor totaled $1,571 million.