Intangible assets consist of trademark and customer lists acquired in the offer under the purchase method of accounting and are recorded at fair value net of accumulated amortization since the purchase date. Amortization is calculated using the straight-line and accelerated methods over the following estimated useful lives:

 

		Useful life
Trademark		10 years
Customer lists		6 years

 

The carrying amount related to acquired intangible assets as of March 31, 2018 are as follows ($ in thousands):

 

Intangible assets at December 31, 2017		$	14,340
Amortization expense			(690)
Intangible assets at March 31, 2018		$	13,650

  

The future amortization of these intangible assets is as follows ($ in thousands):

 

		Trademark			Customer List			Total
Nine Months Ended December 31, 2018		$	226		$	1,884		$	2,110
Year Ended December 31, 2019			300			2,500			2,800
Year Ended December 31, 2020			301			2,506			2,807
Year Ended December 31, 2021			300			2,500			2,800
Year Ended December 31, 2022			300			1,726			2,026
Thereafter			1,107			–			1,107
Total		$	2,534		$	11,116		$	13,650

 

The Company reviews its finite-lived intangible assets for impairment when events or changes in circumstances indicate that the carrying amount of a finite-lived intangible asset may not be recoverable. Recoverability of a finite-lived intangible asset is measured by a comparison of its carrying amount to the undiscounted future cash flows expected to be generated by the asset. If the asset is considered to be impaired, the impairment recognized is measured by the amount by which the carrying amount of the asset exceeds the fair value of the asset. There were no indicators of impairment during the three months ended March 31, 2018.