Inventories

9 Months Ended

Sep. 30, 2022

Inventory Disclosure [Abstract]

Inventories

Inventories

Inventories on the Consolidated Balance Sheets are summarized as follows:

	September 30,		December 31,
(Thousands)	2022		2021
Raw materials and supplies	$	114,225	$	93,518
Work in process	252,077		221,638
Finished goods	53,997		45,959
Inventories, net	$	420,299	$	361,115

The Company maintains the majority of the precious metals and copper used in production on a consignment basis in order to reduce its exposure to metal market price movements and to reduce its working capital investment. The notional value of off-balance sheet precious metals and copper was $354.2 million and $480.2 million as of September 30, 2022 and December 31, 2021, respectively.