Depreciation is computed using the assets’ estimated useful lives as presented below:
Buildings and building improvements
15–44 years
Machinery and equipment
3–30 years
Leasehold improvements
2–20 years
Furniture and fixtures
3–10 years
Computer hardware and software
1–7 years
Property, plant, and equipment, net, consisted of the following:
(thousands of U.S. dollars)
As of December 31,20252024
Land and buildings$470,905 $418,038 
Leasehold improvements128,313 98,028 
Machinery, equipment, including Co-60853,195 757,568 
Furniture and fixtures9,472 9,118 
Computer hardware and software72,694 58,767 
Asset retirement costs7,925 7,368 
Construction-in-progress259,919 250,418 
1,802,423 1,599,305 
Less accumulated depreciation(671,859)(562,413)
Property, plant and equipment, net$1,130,564 $1,036,892 

About PP&E Disclosures

The PP&E disclosure details a company's physical asset base — land, buildings, machinery, and equipment — along with the depreciation methods and useful life assumptions that determine how these costs flow through the income statement. Capitalization policy thresholds reveal management's judgment on the boundary between expense and asset, directly affecting both reported earnings and asset values.

Key signals: changes in estimated useful lives or depreciation methods can materially shift reported earnings without any operational change. Compare capital expenditures against depreciation expense — when capex consistently trails depreciation, the asset base may be aging and underinvested. Watch for large asset impairments or write-downs that signal overvalued carrying amounts. Asset retirement obligations reveal future environmental or decommissioning costs that are often underappreciated. Compare PP&E intensity (PP&E-to-revenue) against industry peers to assess capital efficiency and competitive positioning.