Goodwill and Intangible Assets

Goodwill represents the excess purchase price over the fair value of net assets acquired, or net liabilities assumed, in a business combination. In accordance with ASC Topic 350, Intangibles – Goodwill and Other, the Company performs an annual impairment review in the fourth quarter and more frequently if events or changes in circumstances indicate that goodwill might be impaired. There was no indication that goodwill became impaired as of September 30, 2018.

Other intangible assets include customer relationships, non-compete arrangements, trade names, customer backlog, and internally developed software, which are being amortized over the assets’ estimated useful lives using the straight-line method. Estimated useful lives range from less than one year to ten years. Amortization of customer relationships, non-compete arrangements, trade names, customer backlog, and internally developed software is considered an operating expense and is included in “Amortization” in the accompanying Unaudited Condensed Consolidated Statements of Operations. The Company periodically reviews the estimated useful lives of its identifiable intangible assets, taking into consideration any events or circumstances that might result in a lack of recoverability or revised useful life.

Goodwill

The changes in the carrying amount of goodwill for the nine months ended September 30, 2018 are as follows (in thousands):



Balance at December 31, 2017	$	305,238
Preliminary purchase price allocations for acquisitions	17,267
Effect of foreign currency translation adjustments	(510		)
Balance at September 30, 2018	$	321,995

Intangible Assets with Definite Lives

The following table presents a summary of the Company’s intangible assets that are subject to amortization (in thousands):



	September 30, 2018							December 31, 2017
	Gross Carrying Amounts		Accumulated Amortization			Net Carrying Amounts		Gross Carrying Amounts		Accumulated Amortization			Net Carrying Amounts
Customer relationships	$	80,176	$	(37,781	)	$	42,395	$	75,407	$	(32,307	)	$	43,100
Non-compete agreements	1,626		(789		)	837		1,556		(707		)	849
Customer backlog	1,400		(443		)	957		1,650		(866		)	784
Trade name	110		(43		)	67		100		(53		)	47
Internally developed software	11,900		(6,335		)	5,565		11,325		(5,039		)	6,286
Total	$	95,212	$	(45,391	)	$	49,821	$	90,038	$	(38,972	)	$	51,066

The estimated useful lives of identifiable intangible assets are as follows:



Customer relationships	5 - 10 years
Non-compete agreements	2 - 5 years
Customer backlog	1 - 1.5 years
Trade name	1 year
Internally developed software	2 - 7 years

Estimated annual amortization expense for the next five years ended December 31 and thereafter is as follows and excludes the impact of the acquisition referenced in Note 15, Subsequent Events (in thousands):



2018 remaining	$	4,054
2019	$	14,767
2020	$	11,021
2021	$	8,813
2022	$	7,404
Thereafter	$	3,762