NOTE 6.GOODWILL AND INTANGIBLE ASSETS

The following table summarizes changes in goodwill during the nine months ended September 30, 2022 and the twelve months ended December 31, 2021 (in thousands):

​

The carrying amount of goodwill in foreign countries was $88.9 million as of September 30, 2022 and $82.1 million as of December 31, 2021.

The Company completed its most recent annual impairment analysis as of September 30, 2022. Based upon the results of this analysis, the Company concluded that no impairment of its goodwill or other intangible assets was indicated.

The following table sets forth the components of indefinite-lived and amortizable intangible assets as of September 30, 2022 and December 31, 2021 (in thousands):

​

The carrying amount of customer contracts in foreign countries was $41.6 million and $42.1 million as of September 30, 2022 and December 31, 2021, respectively. The carrying amount of trademarks and tradenames in foreign countries was $4.1 million and $2.9 million as of September 30, 2022 and December 31, 2021, respectively. The carrying amount of other intangible assets in foreign countries was $0.7 million and $0.7 million as of September 30, 2022 and December 31, 2021, respectively.

Amortization expense related to intangible assets was $15.9 million and $13.4 million for the three months ended September 30, 2022 and 2021, respectively. Amortization expense related to intangible assets was $46.7 million and $39.5 million for the nine months ended September 30, 2022 and 2021, respectively. Customer contracts and other amortizable intangible assets are amortized on a straight-line basis over their economic useful lives.

Estimated amortization expense for the existing carrying amount of customer contracts and other intangible assets for each of the five succeeding fiscal years as of September 30, 2022 are as follows:

​

​