9)	Goodwill and Intangible Assets

Goodwill

The Company’s methodology for allocating the purchase price relating to purchase acquisitions is determined through established and generally accepted valuation techniques. Goodwill is measured as the excess of the cost of the acquisition over the sum of the amounts assigned to tangible and identifiable intangible assets acquired less liabilities assumed. The Company assigns assets acquired (including goodwill) and liabilities assumed to one or more reporting units as of the date of acquisition. Typically acquisitions relate to a single reporting unit and thus do not require the allocation of goodwill to multiple reporting units. If the products obtained in an acquisition are assigned to multiple reporting units, the goodwill is distributed to the respective reporting units as part of the purchase price allocation process.

Goodwill and purchased intangible assets with indefinite useful lives are not amortized, but are reviewed for impairment annually during the fourth quarter of each fiscal year and whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable. The process of evaluating the potential impairment of goodwill and intangible assets requires significant judgment. The Company regularly monitors current business conditions and other factors including, but not limited to, adverse industry or economic trends, restructuring actions and lower projections of profitability that may impact future operating results.

Effective July 1, 2018, the Company reassigned goodwill to certain reporting units within the Light & Motion reportable segment resulting from a reorganization of the composition of goodwill reporting units. The goodwill was reassigned to the reporting units affected using the relative fair value approach. In conjunction with this goodwill reassignment, the Company performed an interim quantitative impairment test as of July 1, 2018 for all of its reporting units and concluded that the fair values of each reporting unit exceeded their respective carrying values.

The changes in the carrying amount of goodwill and accumulated impairment loss during the nine months ended September 30, 2018 and year ended December 31, 2017 were as follows:

	Nine Months Ended September 30, 2018									Twelve Months Ended December 31, 2017
	Gross Carrying Amount			Accumulated Impairment Loss			Net			Gross Carrying Amount			Accumulated Impairment Loss			Net
Beginning balance at January 1	$	735,323		$	(144,276	)	$	591,047		$	727,999		$	(139,414	)	$	588,585
Sale of business⁽¹⁾		—			—			—			(3,115	)		—			(3,115	)
Impairment loss⁽²⁾		—			—			—			—			(4,862	)		(4,862	)
Foreign currency translation		(3,186	)		—			(3,186	)		10,439			—			10,439
Ending balance at September 30, 2018 and December 31, 2017	$	732,137		$	(144,276	)	$	587,861		$	735,323		$	(144,276	)	$	591,047

⁽¹⁾

In 2017, the Company sold its Data Analytics Solutions business and, as a result, charged the related goodwill of $(3,115) to the gain on sale of business.

⁽²⁾

In 2017, the Company recorded an impairment loss of $(4,862) related to the write-off of goodwill related to the discontinuation of a product line and consolidation of two manufacturing plants.

Intangible Assets

Components of the Company’s intangible assets are comprised of the following:

As of September 30, 2018:	Gross		Impairment Charges⁽¹⁾			Accumulated Amortization			Foreign Currency Translation			Net
Completed technology	$	172,431	$	(105	)	$	(131,840	)	$	—		$	40,486
Customer relationships		282,744		(1,406	)		(59,260	)		174			222,252
Patents, trademarks, trade names and other		110,523		—			(41,970	)		(3	)		68,550
	$	565,698	$	(1,511	)	$	(233,070	)	$	171		$	331,288

As of December 31, 2017:	Gross		Impairment Charges⁽¹⁾			Accumulated Amortization			Foreign Currency Translation			Net
Completed technology	$	172,431	$	(105	)	$	(115,371	)	$	333		$	57,288
Customer relationships		282,744		(1,406	)		(45,518	)		1,571			237,391
Patents, trademarks, trade names and other		110,523		—			(38,730	)		(74	)		71,719
	$	565,698	$	(1,511	)	$	(199,619	)	$	1,830		$	366,398

⁽¹⁾

In 2017, the Company recorded impairment charges of $1,511 related to the write-off of intangible assets as a result of the discontinuation of a product line and consolidation of two manufacturing plants.

Aggregate amortization expense related to acquired intangibles for the nine months ended September 30, 2018 and 2017 was $32,786 and $34,946, respectively. The amortization expense for the nine months ended September 30, 2018 and 2017 is net of $665 and $588, respectively, of amortization income from unfavorable lease commitments. Aggregate net amortization expense related to acquired intangible assets and unfavorable lease commitments for future years is as follows:

Year	Amount
2018 (remaining)	$	10,760
2019	$	40,144
2020	$	28,125
2021	$	20,248
2022	$	17,619
2023	$	17,253
Thereafter	$	138,955