Intangible assets (Tables)

12 Months Ended

Dec. 31, 2022

Goodwill and Intangible Assets Disclosure [Abstract]

Intangible assets are recorded at cost, or when acquired as a part of a business combination, at estimated fair value, less accumulated amortization. These assets are amortized on a straight-line basis over the useful lives of the assets, which the Company believes is materially consistent with the pattern of economic benefit provided by the assets.


		December 31,
(U.S. Dollars, in thousands)	Weighted Average Amortization Period	2022			2021
Cost
Patents	10.0 years	$	40,108		$	44,561
Developed technology	9.8 years		43,699			43,979
IPR&D	Indefinite		300			300
Customer relationships	7.8 years		15,572			15,621
License and other	9.3 years		23,295			18,924
Trademarks—finite lived	10.0 years		1,875			1,839
	9.3 years		124,849			125,224
Accumulated amortization
Patents		$	(37,506	)	$	(41,408	)
Developed technology			(17,830	)		(13,409	)
Customer relationships			(6,938	)		(4,520	)
License and other			(14,386	)		(12,528	)
Trademarks—finite lived			(801	)		(693	)
			(77,461	)		(72,558	)
Intangible assets, net		$	47,388		$	52,666

Schedule of Future Amortization Expense

Future amortization expense for intangible assets is estimated as follows:


(U.S. Dollars, in thousands)	Amortization
2023	$	9,250
2024		8,705
2025		7,692
2026		6,658
2027		6,470
Thereafter		8,313
Total finite-lived intangible assets, net	$	47,088
Indefinite-lived intangible assets, net		300
Intangible assets, net	$	47,388