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, 2018							December 31, 2019
	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	$	(19,383	)	$	747	$	20,130	$	(19,988	)	$	142
Product lines	10.36	33,858		(17,293		)	16,565		4,846		(1,800		)	3,046
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	$	(43,028	)	$	17,312	$	31,328	$	(28,140	)	$	3,188
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.

In 2019, the Company assessed the recoverability of the Maui product lines and determined that the fair value was less than its carrying amount. As a result, the Company recorded an impairment charge of $9.4 million. The fair value determination is categorized as Level 3 in the fair value hierarchy due to its use of internal projections and unobservable measurement inputs.

For the years ended December 31, 2017, 2018 and 2019, the Company’s aggregate amortization expense related to intangible assets was $8.0 million, $4.9 million and $4.7 million, respectively. The Company currently estimates continuing future amortization expense to be approximately (in thousands):



2020	$	1,158
2021	1,015
2022	1,015
	$	3,188