The changes in the carrying amount of goodwill for the nine months ended September 30, 2022 were as follows:

	As of September 30, 2022
	Weighted- Average Remaining Useful Life - Years		Gross Carrying Amount		Accumulated Amortization		Net
	(in thousands, except years)
Domain names		3.0	$	937	$	529	$	408
Trademarks		1.5		800		411		389
Technology		3.2		338,557		154,903		183,654
Customer relationships		5.8		21,000		5,609		15,391
Patents		9.2		39,279		13,867		25,412
Other		1.3		6,000		2,126		3,874
			$	406,573	$	177,445	$	229,128

	As of December 31, 2021
	Weighted- Average Remaining Useful Life - Years		Gross Carrying Amount		Accumulated Amortization		Net
	(in thousands except years)
Domain names		4.6	$	967	$	365	$	602
Trademarks		4.3		21,384		2,613		18,771
Technology		3.6		343,800		142,588		201,212
Customer relationships		5.1		53,709		6,332		47,377
Patents		4.0		21,195		11,503		9,692
			$	441,055	$	163,401	$	277,654

Amortization of intangible assets was $20.9 million and $107.6 million for the three and nine months ended September 30, 2022, respectively, and $18.1 million and $43.0 million for the three and nine months ended September 30, 2021, respectively. In the second and third quarters of 2022, we revised the useful lives of certain customer relationships, trademarks, domain names, and technology, which resulted in a $43.6 million increase to amortization expense for the nine months ended September 30, 2022.

As of September 30, 2022, the estimated intangible asset amortization expense for the next five years and thereafter is as follows:

	Estimated Amortization
	(in thousands)
Remainder of 2022	$	24,741
2023		70,110
2024		57,168
2025		41,092
2026		16,664
Thereafter		19,353
Total	$	229,128