Intangibles

The company's intangibles consist of the following (in thousands):



	March 31, 2017				December 31, 2016
	Historical Cost		Accumulated Amortization		Historical Cost		Accumulated Amortization
Customer lists	$	49,351	$	46,110	$	49,362	$	45,797
Trademarks	24,088		—		24,091		—
Developed technology	7,283		6,009		7,287		5,969
Patents	5,532		5,521		5,512		5,487
License agreements	1,137		1,137		1,126		1,126
Other	1,162		1,140		1,162		1,138
Intangibles	$	88,553	$	59,917	$	88,540	$	59,517

All of the company’s intangible assets have been assigned definite lives and continue to be amortized over their useful lives, except for trademarks shown above, which have indefinite lives. The changes in intangible balances reflected on the balance sheet from December 31, 2016 to March 31, 2017 were the result of foreign currency translation and amortization.

The company evaluates the carrying value of definite-lived assets whenever events or circumstances indicate possible impairment. Definite-lived assets are determined to be impaired if the future un-discounted cash flows expected to be generated by the asset are less than the carrying value. Actual impairment amounts for definite-lived assets are then calculated using a discounted cash flow calculation. The company reviews indefinite-lived assets for impairment annually in the fourth quarter of each year and whenever events or circumstances indicate possible impairment. Any impairment amounts for indefinite-lived assets are calculated as the difference between the future discounted cash flows expected to be generated by the asset less than the carrying value for the asset.

Amortization expense related to intangibles was $380,000 in the first three months of 2017 and is estimated to be $1,481,000 in 2017, $1,462,000 in 2018, $1,161,000 in 2019, $170,000 in 2020, $170,000 in 2021 and $170,000 in 2022. Amortized intangibles are being amortized on a straight-line basis over remaining lives of 1 to 10 years with the majority of the intangibles being amortized over an average remaining life of approximately 4 years.