7. INTANGIBLE ASSETS

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


					March 31, 2019						December 31, 2018
					Gross		Accumulated		Net Book		Gross		Accumulated		Net Book
	Life				Amount		amortization		Value		Amount		amortization		Value
Customer lists	8	-	17	years	$	64,316	$	(16,297)	$	48,019	$	64,439	$	(15,343)	$	49,096
Trade name	10	-	19	years		12,222		(3,502)		8,720		12,249		(3,305)		8,944
Design and technologies	10	-	15	years		12,928		(2,893)		10,035		13,023		(2,723)		10,300
Patents	17			years		24		(10)		14		24		(10)		14
Total					$	89,490	$	(22,702)	$	66,788	$	89,735	$	(21,381)	$	68,354

Intangible assets resulting from the acquisition of TCI were approximately $36,400 (Note 2). The intangible assets acquired consist of customer lists, a trade name and technology. The valuation and useful life of the purchased intangibles has not been finalized.

Intangible assets from the acquisition of the Maval OE Steering business were approximately $3,870 (Note 2). The intangible assets acquired consist of customer lists.

Amortization expense for intangible assets was $1,432 and $884 for the quarters ended March 31, 2019 and March 31, 2018, respectively.

Estimated future intangible asset amortization expense as of March 31, 2019 is as follows (in thousands):


	Estimated
	Amortization
	Expense
Remainder of 2019	$	4,289
2020		5,719
2021		5,470
2022		5,470
2023		5,389
2024		5,087
Thereafter		35,364
Total estimated amortization expense	$	66,788