INTANGIBLE ASSETS

6 Months Ended

Jun. 30, 2020

INTANGIBLE ASSETS

INTANGIBLE ASSETS

7.    INTANGIBLE ASSETS

Intangible assets on the Company’s condensed consolidated balance sheets consist of the following (in thousands):

		June 30, 2020						December 31, 2019
		Gross		Accumulated		Net Book		Gross		Accumulated		Net Book
	Life	Amount		amortization		Value		Amount		amortization		Value
Customer lists	8 - 17 years	$	68,698	$	(21,315)	$	47,383	$	64,314	$	(19,311)	$	45,003
Trade name	10 - 19 years		13,733		(4,549)		9,184		12,222		(4,114)		8,108
Design and technologies	10 - 15 years		14,836		(4,037)		10,799		12,927		(3,554)		9,373
Patents	17 years		24		(12)		12		24		(11)		13
Total		$	97,291	$	(29,913)	$	67,378	$	89,487	$	(26,990)	$	62,497

Intangible assets resulting from the acquisition of Dynamic Controls were $7,800 (Note 2). The intangible assets acquired consist of a customer list, a trade name and technology.

Amortization expense for intangible assets was $1,483 and $1,430 for the quarters ended June 30, 2020 and 2019, respectively. For the six months ended June 30, 2020 and 2019, amortization expense was $2,924 and $2,862, respectively.

Estimated future intangible asset amortization expense as of June 30, 2020 is as follows (in thousands):

	Estimated
	Amortization Expense
Remainder of 2020	$	2,976
2021		5,945
2022		5,990
2023		5,996
2024		5,670
Thereafter		40,801
Total estimated amortization expense	$	67,378