INTANGIBLE ASSETS

A summary of intangible assets as of December 31, 2018 and 2017 is as follows (in thousands):



	December 31, 2018
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Customer relationships	$	174,894	$	(51,160	)	$	123,734
Non-compete agreements	5,433		(4,882		)	551
Trade names	24,753		(20,594		)	4,159
Technology	7,847		(5,187		)	2,660
Licenses	851		(583		)	268
Total	$	213,778	$	(82,406	)	$	131,372



	December 31, 2017
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Customer relationships	$	175,226	$	(38,712	)	$	136,514
Non-compete agreements	5,563		(4,509		)	1,054
Trade names	24,830		(6,211		)	18,619
Technology	7,867		(4,292		)	3,575
Licenses	859		(460		)	399
Total	$	214,345	$	(54,184	)	$	160,161

Amortization expense for the years ended December 31, 2018, 2017 and 2016 was $28.7 million, $16.5 million and $16.1 million, respectively. Amortization expense for current intangible assets is forecast to be approximately $14 million per year in 2019 and 2020 and approximately $13 million per year in 2021, 2022 and 2023. The higher amortization expense in 2018 is primarily due to a change in the estimated useful life of intangible asset associated with the Furmanite trade name. Management determined that, as a result of initiatives to consolidate the Company’s branding, the useful life of this intangible asset was not expected to extend beyond December 31, 2018. In accordance with ASC 350, we accounted for the change in useful life prospectively effective January 1, 2018 and amortized the remaining balance over 2018, which resulted in incremental amortization expense in 2018 of $12 million. The weighted-average amortization period for intangible assets subject to amortization was 13.5 years as of December 31, 2018. The weighted-average amortization period as of December 31, 2018 is 13.6 years for customer relationships, 4.7 years for non-compete agreements, 14.3 years for trade names, 9.9 years for technology and 10.6 years for licenses.