Note 8. Other Intangible Assets, Net

Other intangible assets consisted of the following:

Amortization expense

Amortization expense relating to intangible assets for the years ended December 31, 2019, 2018 and 2017, was approximately $25.2 million, $32.4 million and $35.0 million, respectively. The decrease in amortization expense in 2019 was primarily due to change in the estimated useful lives of certain intangibles assets as of December 31, 2018.

As of December 31, 2019, estimated future amortization expense relating to definite life intangible assets for each of the next five years and thereafter were as follows:

During the years ended December 31, 2018 and 2017, the Company recorded impairment charges of $2.2 million in each of the two years, related to its definite life intangible assets. No impairment charges were recorded during 2019.