Goodwill and Purchased Intangible Assets (Tables)

9 Months Ended

Sep. 30, 2021

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Goodwill

The Company's goodwill activity during the nine months ended September 30, 2021 was as follows (in millions):

	Total
December 31, 2020	$	3,669.6
Additions due to business combinations	84.5
September 30, 2021	$	3,754.1

Schedule of Acquired Indefinite-Lived Intangible Assets by Major Class

The Company’s purchased intangible assets, net, were as follows (in millions):

	As of September 30, 2021								As of December 31, 2020
	Gross		Accumulated Amortization		Accumulated Impairments and Other Charges		Net		Gross		Accumulated Amortization		Accumulated Impairments and Other Charges		Net
Finite-lived intangible assets:
Technologies and patents	$	903.8	$	(644.8)	$	(55.1)	$	203.9	$	823.5	$	(598.2)	$	(55.1)	$	170.2
Customer relationships	136.3		(95.0)		(2.8)		38.5		129.2		(84.4)		(2.8)		42.0
Trade names and other	9.6		(5.9)		—		3.7		9.6		(4.1)		—		5.5
Total	1,049.7		(745.7)		(57.9)		246.1		962.3		(686.7)		(57.9)		217.7
Indefinite-lived intangible assets:
In-process research and development	49.0		—		—		49.0		49.0		—		—		49.0
Total purchased intangible assets	$	1,098.7	$	(745.7)	$	(57.9)	$	295.1	$	1,011.3	$	(686.7)	$	(57.9)	$	266.7

Schedule of Acquired Finite-Lived Intangible Assets by Major Class

The Company’s purchased intangible assets, net, were as follows (in millions):

	As of September 30, 2021								As of December 31, 2020
	Gross		Accumulated Amortization		Accumulated Impairments and Other Charges		Net		Gross		Accumulated Amortization		Accumulated Impairments and Other Charges		Net
Finite-lived intangible assets:
Technologies and patents	$	903.8	$	(644.8)	$	(55.1)	$	203.9	$	823.5	$	(598.2)	$	(55.1)	$	170.2
Customer relationships	136.3		(95.0)		(2.8)		38.5		129.2		(84.4)		(2.8)		42.0
Trade names and other	9.6		(5.9)		—		3.7		9.6		(4.1)		—		5.5
Total	1,049.7		(745.7)		(57.9)		246.1		962.3		(686.7)		(57.9)		217.7
Indefinite-lived intangible assets:
In-process research and development	49.0		—		—		49.0		49.0		—		—		49.0
Total purchased intangible assets	$	1,098.7	$	(745.7)	$	(57.9)	$	295.1	$	1,011.3	$	(686.7)	$	(57.9)	$	266.7

Estimated Future Amortization Expense of Purchased Intangible Assets with Finite Lives

As of September 30, 2021, the estimated future amortization expense of purchased intangible assets with finite lives is as follows (in millions):

Years Ending December 31,	Amount
Remainder of 2021	$	20.1
2022	72.8
2023	66.9
2024	47.4
2025	37.8
Thereafter	1.1
Total	$	246.1