INTANGIBLE ASSETS

Intangible assets are comprised as follows:



(in thousands)			December 31, 2018
	Gross Carrying Value			Accumulated Amortization		Net Carrying Value
Intangible assets subject to amortization
Database	$	4,918		$	3,013	$	1,905
Vehicle service agreements in-force	3,680			3,671		9
Customer relationships	8,914			3,691		5,223
In-place lease	1,125			155		970
Non-compete	266			64		202
Intangible assets not subject to amortization
Tenant relationship	73,667			—		73,667
Trade names	1,290			—		1,290
Total	$	93,860		$	10,594	$	83,266



(in thousands) (restated)			December 31, 2017
	Gross Carrying Value			Accumulated Amortization		Net Carrying Value
Intangible assets subject to amortization
Database	$	4,918		$	2,521	$	2,397
Vehicle service agreements in-force	3,680			3,640		40
Customer relationships	3,611			1,965		1,646
In-place lease	1,125			92		1,033
Intangible assets not subject to amortization
Tenant relationship	73,667			—		73,667
Trade name	663			—		663
Total	$	87,664		$	8,218	$	79,446

As further discussed in Note 5, "Acquisition," during the third quarter of 2018, the Company recorded $6.2 million of separately identifiable intangible assets, related to acquired customer relationships, non-compete agreement and trade name, as part of the acquisition of PWSC. The customer relationships intangible asset of $5.3 million is being amortized over fifteen years based on the pattern in which the economic benefits of the intangible asset are expected to be consumed. The non-compete agreement intangible asset of $0.3 million is being amortized on a straight-line basis over five years. The trade name intangible asset of $0.6 million is deemed to have an indefinite useful life and is not amortized.

The Company's other intangible assets with definite useful lives are amortized either based on the patterns in which the economic benefits of the intangible assets are expected to be consumed or using the straight-line method over their estimated useful lives, which range from seven to eighteen years. Amortization of intangible assets was $2.4 million and $1.1 million for the years ended December 31, 2018 and December 31, 2017, respectively. The estimated aggregate future amortization expense of all intangible assets is $1.8 million for 2019, $1.5 million for 2020, $1.4 million for 2021, $1.1 million for 2022 and $0.5 million for 2023.

The tenant relationship and trade names intangible assets have indefinite useful lives and are not amortized. All intangible assets with indefinite useful lives are reviewed annually by the Company for impairment. No impairment charges were taken on intangible assets in 2018 or 2017.