The following table summarizes the changes in the carrying amount of goodwill (in millions):


	Amount
Balance at December 31, 2021	$	188.3
Acquisitions	8.8
Measurement period adjustments	1.3
Balance at December 31, 2022	198.4
Acquisitions	11.4
Balance at December 31, 2023	$	209.8

The following table summarizes the carrying amounts and accumulated amortization of intangible assets (in millions, except weighted-average remaining useful life):


	December 31, 2023
	Useful Life	Gross Carrying Amount		Accumulated Amortization		Net Value		Weighted Average Remaining Useful Life (Years)
Finite-lived intangible assets:
Customer relationships	2-9 years	$	160.1	$	(92.0)	$	68.1	2.9
Acquired technology	5 years	5.5		(2.9)		2.6		2.3
Trademarks	2-9 years	12.5		(5.9)		6.6		4.2
Indefinite-lived intangible assets:
Domain name		0.3		—		0.3		n/a
Total		$	178.4	$	(100.8)	$	77.6


	December 31, 2022
	Useful Life	Gross Carrying Amount		Accumulated Amortization		Net Value		Weighted Average Remaining Useful Life (Years)
Finite-lived intangible assets:
Customer relationships	2-9 years	$	155.2	$	(68.6)	$	86.6	3.4
Acquired technology	5 years	5.5		(1.8)		3.7		3.3
Trademarks	2-9 years	13.0		(4.3)		8.7		4.9
Indefinite-lived intangible assets:
Domain name		0.3		—		0.3		n/a
Total		$	174.0	$	(74.7)	$	99.3

Amortization expense was $32.9 million, $38.1 million and $25.9 million for the years ended December 31, 2023, 2022 and 2021, respectively.

Estimated future amortization expense for finite-lived intangible assets as of December 31, 2023 is as follows (in millions):