The goodwill acquired for Information Services shown above relates to our acquisition of Solovis. See “2020 Acquisition,” of Note 4, “Acquisitions and Divestiture,” for further discussion of this acquisition.

Goodwill represents the excess of purchase price over the value assigned to the net assets, including identifiable intangible assets, of a business acquired. Goodwill is allocated to our reporting units based on the assignment of the fair values of each reporting unit of the acquired company. We test goodwill for impairment at the reporting unit level annually, or in interim periods if certain events

occur indicating that the carrying amount may be impaired, such as changes in the business climate, poor indicators of operating performance or the sale or disposition of a significant portion of a reporting unit. There was no impairment of goodwill for the nine months ended September 30, 2020 and 2019; however, events such as extended economic weakness or unexpected significant declines in operating results of any of our reporting units or businesses may result in goodwill impairment charges in the future.

Acquired Intangible Assets

The following table presents details of our total acquired intangible assets, both finite- and indefinite-lived:


	September 30, 2020						December 31, 2019
	Gross Amount		Accumulated Amortization		Net Amount		Gross Amount		Accumulated Amortization		Net Amount
	(in millions)						(in millions)
Finite-Lived Intangible Assets
Technology	$	76	$	(21)	$	55	$	63	$	(19)	$	44
Customer relationships	1,599		(624)		975		1,596		(532)		1,064
Other	18		(6)		12		18		(5)		13
Foreign currency translation adjustment	(151)		77		(74)		(159)		55		(104)
Total finite-lived intangible assets	$	1,542	$	(574)	$	968	$	1,518	$	(501)	$	1,017
Indefinite-Lived Intangible Assets
Exchange and clearing registrations	$	1,257	$	—	$	1,257	$	1,257	$	—	$	1,257
Trade names	121		—		121		121		—		121
Licenses	52		—		52		52		—		52
Foreign currency translation adjustment	(180)		—		(180)		(198)		—		(198)
Total indefinite-lived intangible assets	$	1,250	$	—	$	1,250	$	1,232	$	—	$	1,232
Total intangible assets	$	2,792	$	(574)	$	2,218	$	2,750	$	(501)	$	2,249

Amortization expense for acquired finite-lived intangible assets was $26 million for the three months ended September 30, 2020, $25 million for the three months ended September 30, 2019, and $76 million for both the nine months ended September 30, 2020 and 2019. These amounts are included in depreciation and amortization expense in the Condensed Consolidated Statements of Income.

The estimated future amortization expense (excluding the impact of foreign currency translation adjustments of $74 million as of September 30, 2020) of acquired finite-lived intangible assets as of September 30, 2020 is as follows:


	(in millions)
2020(1)	$	27
2021	109
2022	106
2023	103
2024	98
2025 and thereafter	599
Total	$	1,042

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(1) Represents the estimated amortization to be recognized over the remaining three months of 2020.