10 INTANGIBLE ASSETS

Intangible assets at June 30, 2018 and December 31, 2017 are comprised as follows:



(in thousands)			June 30, 2018
	Gross Carrying Value			Accumulated Amortization		Net Carrying Value
Intangible assets subject to amortization:
Database	$	4,918		$	2,767	$	2,151
Vehicle service agreements in-force	3,680			3,656		24
Customer relationships	3,611			2,183		1,428
In-place lease	1,125			123		1,002
Intangible assets not subject to amortization:
Tenant relationship	73,667			—		73,667
Trade name	663			—		663
Total	$	87,664		$	8,729	$	78,935



(in thousands)			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

The Company's 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 $0.3 million and $0.3 million for the three months ended June 30, 2018 and June 30, 2017, respectively ($0.5 million and $0.5 million for the six months ended June 30, 2018 and June 30, 2017, respectively).

The tenant relationship and trade name intangible assets have indefinite useful lives and are not amortized. No impairment charges were taken on intangible assets during the three and six months ended June 30, 2018 and June 30, 2017.