The following table sets forth the changes in the carrying amount of goodwill by segment (in millions):


	BSI BioSpin			BSI CALID			BSI Nano			BEST		Total
Balance at December 31, 2020	$	30.8		$	61.3		$	228.0		$	0.3	$	320.4
Current period additions/adjustments		12.8			0.6			16.6			—		30.0
Foreign currency impact		(1.2	)		(4.0	)		(5.7	)		—		(10.9	)
Balance at December 31, 2021		42.4			57.9			238.9			0.3		339.5
Current period additions/adjustments		18.6			55.3			58.0			—		131.9
Foreign currency impact		(3.2	)		(5.8	)		(4.8	)		—		(13.8	)
Balance at December 31, 2022		57.8			107.4			292.1			0.3		457.6
Current period additions/adjustments		25.8			83.8			(0.5	)		—		109.1
Foreign currency impact		2.9			10.3			2.7			—		15.9
Balance at December 31, 2023	$	86.5		$	201.5		$	294.3		$	0.3	$	582.6

The Company has historically evaluated its goodwill for impairment annually as of December 31 or more frequently if impairment indicators arose in accordance with Accounting Standards Codification (“ASC”) Topic 350, “Intangibles - Goodwill and Other.” In the fourth quarter of 2022, the Company changed the date of its annual assessment of goodwill to October 1st for all reporting units. The change in testing date for goodwill is a change in accounting principle, which management believes is preferable as the new date of the assessment better aligns with the Company’s budgeting process and will create a more efficient and timely process surrounding the impairment tests. The change in the assessment date does not delay, accelerate or avoid a potential impairment charge. The Company has determined that it is impracticable to objectively determine projected cash flows and related valuation estimates that would have been used as of each October 1st of prior reporting periods without the use of hindsight. As such, the Company prospectively applied the change in annual goodwill impairment testing date from October 1, 2022. No impairment was recognized during the years ended December 31, 2023, 2022, or 2021.

The following is a summary of intangible assets (in millions):


	2023							2022
	Gross					Net		Gross					Net
	Carrying		Accumulated			Carrying		Carrying		Accumulated			Carrying
	Amount		Amortization			Amount		Amount		Amortization			Amount
Existing technology and related patents	$	428.3	$	(250.4	)	$	177.9	$	354.7	$	(219.0	)	$	135.7
Customer relationships		227.4		(93.5	)		133.9		192.3		(72.1	)		120.2
Trade names		28.4		(10.1	)		18.3		22.3		(7.4	)		14.9
Other		2.2		(1.8	)		0.4		1.0		(0.9	)		0.1
Intangible assets	$	686.3	$	(355.8	)	$	330.5	$	570.3	$	(299.4	)	$	270.9

For the years ended December 31, 2023, 2022 and 2021, the Company recorded amortization expense of approximately $47.1 million, $37.1 million and $37.4 million, respectively, in the consolidated statements of income and comprehensive income. At December 31, 2023, the net carrying amount of trade names includes $3.0 million related to indefinite-lived intangible assets which are not amortized but are evaluated for impairment.

On a quarterly basis, the Company reviews its intangible assets to determine if there have been any triggering events that could indicate an impairment. In connection with certain restructuring programs initiated in 2023, the Company performed impairment assessments of its long-lived assets comparing the carrying values to the sum of their undiscounted future cash flows. Based on the results of these analyses, the Company determined there were no impairments to its long-lived assets, including intangible assets and goodwill. No other triggering events were identified for the years ended December 31, 2023, and 2022. See Note 21, Other Charges, Net for discussion related to impairment of other long-lived assets in connection with the BCA restructuring plan.