Property, plant and equipment

12 Months Ended

Dec. 31, 2024

Property, Plant and Equipment [Abstract]

Property, plant and equipment

6. Property, plant, and equipment

Property, plant, and equipment is stated at cost or estimated fair value when acquired as part of a business combination, less accumulated depreciation. Costs include all expenditures necessary to place the asset in service, generally including freight and sales and use taxes. Property, plant, and equipment also includes instrumentation, which is generally used to facilitate the implantation of the Company’s products.

The useful lives of these assets are generally as follows:

	Years
Buildings	25 to 33
Plant and equipment	1 to 10
Instrumentation	3 to 4
Computer software	3 to 7
Furniture and fixtures	4 to 8

The Company evaluates the useful lives of these assets on an annual basis. Depreciation is computed on a straight-line basis over the useful lives of the assets. Depreciation of leasehold improvements is computed over the shorter of the lease term or the useful life of the asset. Total depreciation expense was $41.1 million, $34.2 million, and $19.6 million for the years ended December 31, 2024, 2023, and 2022, respectively.

Expenditures for maintenance and repairs and minor renewals and improvements, which do not extend the lives of the respective assets, are expensed as incurred. All other expenditures for renewals and improvements are capitalized. The assets and related accumulated depreciation are adjusted for property retirements and disposals, with the resulting gain or loss included in earnings. Fully depreciated assets remain in the accounts until retired from service.

	December 31,
(U.S. Dollars, in thousands)	2024			2023
Cost
Buildings	$	3,874		$	4,103
Plant and equipment		76,481			70,252
Instrumentation		176,387			154,192
Computer software		41,396			43,040
Furniture and fixtures		9,832			11,010
Construction in progress		22,693			41,751
Finance lease assets		21,383			23,337
Property, plant, and equipment, gross		352,046			347,685
Accumulated depreciation		(212,242	)		(188,625	)
Property, plant, and equipment, net	$	139,804		$	159,060

The Company capitalizes system development costs related to internal-use software during the application development stage. Costs related to preliminary project activities and post-implementation activities are expensed as incurred. Internal-use software is amortized on a straight-line basis over its estimated useful life, which generally ranges from three to seven years.

Long-lived assets are evaluated for impairment annually or whenever events or changes in circumstances have occurred that would indicate impairment. For purposes of the evaluation, the Company groups its long-lived assets with other assets and liabilities at the lowest level of identifiable cash flows if the asset does not generate cash flows independent of other assets and liabilities. If the carrying value of the asset or asset group exceeds the undiscounted cash flows expected to result from the use and eventual disposition of the asset group, the Company will write the carrying value down to fair value in the period identified.

The Company generally determines fair value of long-lived assets as the present value of estimated future cash flows. In determining the estimated future cash flows associated with the assets, the Company uses estimates and assumptions about future revenue contributions, cost structures, and remaining useful lives of the asset group. The use of alternative assumptions, including estimated cash flows, discount rates, and alternative estimated remaining useful lives could result in different calculations of impairment.