Note 5: Goodwill and Intangible Assets

Goodwill

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



	As of
	September 28, 2018							December 31, 2017
	Goodwill		Accumulated Impairment Losses			Carrying Value		Goodwill		Accumulated Impairment Losses			Carrying Value
Operating and Reporting Segments:
Power Solutions Group	$	432.2	$	(31.9	)	$	400.3	$	432.2	$	(28.6	)	$	403.6
Analog Solutions Group	836.7		(418.9		)	417.8		836.7		(418.9		)	417.8
Intelligent Sensing Group	114.4		—			114.4		95.5		—			95.5
	$	1,383.3	$	(450.8	)	$	932.5	$	1,364.4	$	(447.5	)	$	916.9

The following table summarizes the change in goodwill from December 31, 2017 to September 28, 2018 (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 September 28, 2018	$	932.5

During the quarter ended June 29, 2018, the Company recorded a goodwill impairment charge of $3.3 million, which represented the entire goodwill assigned to a reporting unit within the Power Solutions Group as a result of the licensing transaction with QST. See Note 4: ''Acquisitions, Divestitures and Licensing Transactions'' for more information.

Goodwill is tested for impairment annually on the first day of the fourth quarter or more frequently if events or changes in circumstances (each, a "triggering event") would more likely than not reduce the carrying value of goodwill below its fair value. Management did not identify any triggering events through September 28, 2018 that would require an interim impairment analysis.

Intangible Assets

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



	As of September 28, 2018
	Original Cost		Accumulated Amortization			Accumulated Impairment Losses			Carrying Value
Customer relationships	$	556.7	$	(351.4	)	$	(20.1	)	$	185.2
Developed technology	698.0		(336.4		)	(2.6		)	359.0
IPRD	64.1		—			(19.0		)	45.1
Other intangibles	79.9		(58.1		)	(15.2		)	6.6
Total intangible assets	$	1,398.7	$	(745.9	)	$	(56.9	)	$	595.9



	As of December 31, 2017
	Original Cost		Accumulated Amortization			Accumulated Impairment Losses			Carrying Value
Customer relationships	$	555.9	$	(328.5	)	$	(20.1	)	$	207.3
Developed technology	657.6		(278.2		)	(2.6		)	376.8
IPRD	54.5		—			(19.0		)	35.5
Other intangibles	79.8		(55.9		)	(15.2		)	8.7
Total intangible assets	$	1,347.8	$	(662.6	)	$	(56.9	)	$	628.3

Amortization expense for acquisition-related intangible assets amounted to $28.0 million and $83.3 million for the quarter and nine months ended September 28, 2018, respectively, and $37.3 million and $95.0 million for the quarter and nine months ended September 29, 2017, respectively. Amortization expense for intangible assets, with the exception of the $45.1 million of IPRD assets that will be amortized once the corresponding projects have been completed, is expected to be as follows for the remainder of 2018, each of the next four years and thereafter (in millions):



Period	Amortization Expense
Remainder of 2018	$	28.2
2019	105.9
2020	95.4
2021	78.3
2022	63.4
Thereafter	179.6
Total	$	550.8