GOODWILL AND OTHER INTANGIBLE ASSETS

12 Months Ended

Dec. 31, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill and in-process research and development assets resulting from purchase business combinations are not subject to amortization. Other acquired intangible assets with finite lives are amortized over their expected useful lives on a straight-line basis, or if reliably determinable, based on the pattern in which the economic benefit of the asset is expected to be used. The Company expenses costs incurred to renew or extend the term of acquired intangible assets.

In April 2019, the Company acquired CASMED. This transaction resulted in an increase to goodwill of $64.4 million and developed technology of $35.9 million. For further information, see Note 8.

The changes in the carrying amount of goodwill, by segment, during the years ended December 31, 2020 and 2019 were as follows:


	United States		Europe		Rest of World		Total
	(in millions)
Goodwill at December 31, 2018	$	709.3	$	64.2	$	338.7	$	1,112.2
Goodwill acquired during the year	64.4		—		—		64.4
Currency translation adjustment	—		(1.4)		(7.5)		(8.9)
Goodwill at December 31, 2019	773.7		62.8		331.2		1,167.7

Currency translation adjustment	—		5.5		—		5.5
Goodwill at December 31, 2020	$	773.7	$	68.3	$	331.2	$	1,173.2

Other intangible assets consist of the following (in millions):


		December 31,
	Weighted-Average Useful Life (in years)	2020						2019
		Cost		Accumulated Amortization		Net Carrying Value		Cost		Accumulated Amortization		Net Carrying Value
Finite-lived intangible assets
Patents	7.4	$	186.1	$	(183.6)	$	2.5	$	185.7	$	(182.1)	$	3.6
Developed technology	13.1	155.2		(51.0)		104.2		153.5		(46.6)		106.9
Other	10.0	12.6		(6.0)		6.6		12.3		(4.4)		7.9
	12.6	353.9		(240.6)		113.3		351.5		(233.1)		118.4
Indefinite-lived intangible assets
In-process research and development		218.1		—		218.1		218.1		—		218.1
		$	572.0	$	(240.6)	$	331.4	$	569.6	$	(233.1)	$	336.5

Amortization expense related to other intangible assets for the years ended December 31, 2020, 2019, and 2018 was $5.4 million, $4.6 million, and $2.5 million, respectively. Estimated amortization expense for each of the years ending December 31 is as follows (in millions):


2021	$	5.2
2022	7.6
2023	10.1
2024	12.2
2025	14.8