Intangible Assets Other Than Goodwill

Intangible assets other than goodwill consist primarily of licenses, product lines, customer relationships and trademarks. Amortized intangible assets are included in intangibles in the accompanying consolidated balance sheets. Trademarks are disclosed separately in the accompanying consolidated balance sheets. Intangible assets are as follows (in thousands, except for weighted useful lives):



		December 31, 2017							December 31, 2018
	Weighted Useful Lives	Gross Carrying Amount		Accumulated Amortization			Net Amount		Gross Carrying Amount		Accumulated Amortization			Net Amount
	(Years)
Amortized Intangible Assets:
Licenses	5.81	$	20,130	$	(18,620	)	$	1,510	$	20,130	$	(19,383	)	$	747
Product lines	10.36	33,858		(13,178		)	20,680		33,858		(17,293		)	16,565
Customer relationships	4.90	3,152		(3,152		)	—		3,152		(3,152		)	—
Trade names	5.00	3,000		(3,000		)	—		3,000		(3,000		)	—
Non-compete agreements	5.00	200		(200		)	—		200		(200		)	—
Total amortized intangible assets		$	60,340	$	(38,150	)	$	22,190	$	60,340	$	(43,028	)	$	17,312
Unamortized Intangible Assets:
Trademarks		$	300	$	—		$	300	$	300	$	—		$	300

In 2017, the Company recorded impairment charges of $2.9 million to write off the remaining unamortized technology rights related to DreamPlay, LLC which were included in product lines, and $2.3 million to write down several underutilized trademarks and trade names that were determined to have no value. No impairment charges were recorded for the year ended December 31, 2018.

For the years ended December 31, 2016, 2017 and 2018, the Company’s aggregate amortization expense related to intangible assets was $8.8 million, $8.0 million and $4.9 million, respectively. The Company currently estimates continuing future amortization expense to be approximately (in thousands):



2019	$	4,747
2020	4,284
2021	4,141
2022	4,140
	$	17,312