Goodwill and Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2019

Goodwill and Intangible Assets Disclosure [Abstract]

Summary of Goodwill by Operating Segment

The following table summarizes goodwill by operating and reportable segments (in millions):


	As of December 31, 2019										As of December 31, 2018									As of December 31, 2017
	Goodwill		Accumulated Impairment Losses		Carrying Value		Goodwill		Accumulated Impairment Losses			Carrying Value		Goodwill		Accumulated Impairment Losses		Carrying Value
Operating and Reportable Segments:
ASG	$	1,563.4	$	(418.9)	$	1,144.5	$	836.7	$	(418.9)		$	417.8	$	836.7	$	(418.9)	$	417.8
ISG	114.4		—		114.4		114.4		—			114.4		95.5		—		95.5
PSG	432.2		(31.9)		400.3		432.2		(31.9)			400.3		432.2		(28.6)		403.6
Total	$	2,110.0	$	(450.8)	$	1,659.2	$	1,383.3	$	(450.8)		$	932.5	$	1,364.4	$	(447.5)	$	916.9

Schedule of Change in Goodwill

The following table summarizes the change in goodwill (in millions):


Net balance as of December 31, 2017	$	916.9
Addition due to business combination	18.9
Goodwill impairment	(3.3)
Net balance as of December 31, 2018	932.5
Addition due to business combination	726.7

Net balance as of December 31, 2019	$	1,659.2

Summary of Intangible Assets, Net

Intangible assets, net, were as follows (in millions):


	As of December 31, 2019
	Original Cost		Accumulated Amortization		Accumulated Impairment Losses		Carrying Value

Customer relationships	$	585.2	$	(386.8)	$	(20.1)	$	178.3

Developed technology	779.5		(440.3)		(2.6)		336.6



IPRD	64.7		—		(24.1)		40.6
Licenses	30.0		—		—		30.0
Other intangibles	79.3		(59.1)		(15.2)		5.0
Total intangible assets	$	1,538.7	$	(886.2)	$	(62.0)	$	590.5


	As of December 31, 2018
	Original Cost		Accumulated Amortization		Accumulated Impairment Losses		Carrying Value

Customer relationships	$	556.7	$	(359.1)	$	(20.1)	$	177.5

Developed technology	698.0		(356.4)		(2.6)		339.0



IPRD	64.1		—		(22.5)		41.6
Other intangibles	82.3		(58.8)		(15.2)		8.3
Total intangible assets	$	1,401.1	$	(774.3)	$	(60.4)	$	566.4

Summary of Amortization Expense

Amortization expense for intangible assets, with the exception of the $40.6 million of IPRD assets that will be amortized once the corresponding projects have been completed, is expected to be as follows over the next five years, and thereafter (in millions):


	Total
2020	$	116.5
2021	94.9
2022	80.6
2023	63.2
2024	52.1
Thereafter	142.6
Total estimated amortization expense	$	549.9