Goodwill and indefinite-lived intangible assets are not amortized and are subject to assessment for impairment by applying a fair-value-based test on an annual basis or more frequently if circumstances indicate a potential impairment. An assessment for impairment is performed on October 1 of every year. The balance of goodwill was $512 million and $501 million as of September 30, 2020 and December 31, 2019, respectively. The increase in goodwill reflects adjustments related to our acquisition of Streem. See Note 7 to the accompanying condensed consolidated financial statements for further information. There were no goodwill or trade name impairment charges recorded in the nine months ended September 30, 2020 and 2019. There were no accumulated impairment losses recorded as of September 30, 2020 and December 31, 2019. During the second quarter of 2020, we completed a business acquisition for $5 million, which was primarily allocated to developed technology and other intangible assets.



	As of September 30, 2020						As of December 31, 2019
(In millions)	Gross		Accumulated ‎Amortization		Net		Gross		Accumulated ‎Amortization		Net
Trade names⁽¹⁾	$	141	$	—	$	141	$	141	$	—	$	141
Customer relationships		173		(170)		2		173		(168)		5
Developed technology		25		(5)		20		34		(1)		33
Other		37		(27)		9		37		(25)		12
Total	$	375	$	(202)	$	173	$	385	$	(193)	$	191

Amortization expense was $2 million and $1 million for the three months ended September 30, 2020 and 2019, respectively, and $9 million and $5 million for the nine months ended September 30, 2020 and 2019, respectively. The following table outlines expected amortization expense for existing intangible assets for the remainder of 2020 and the next five years:



(In millions)
2020 (remainder)	$	3
2021		11
2022		8
2023		6
2024		4
2025		—
Total	$	32