Inventories (Tables)

12 Months Ended

Dec. 31, 2020

Accounts Receivable and Inventories [Abstract]

Schedule of inventories

Inventories consist of the following:

(In thousands)	December 31 2020		December 31 2019
Finished goods	$	8,505	$	14,550
Work-in-process	16,522		13,088
Raw materials and purchased parts	117,789		104,488
Stores and supplies	30,197		24,865
Total inventories	$	173,013	$	156,991
Valued at lower of cost or market:
LIFO basis	$	107,162	$	101,465
FIFO basis	17,655		7,473
Average cost basis	48,196		48,053
Total inventories	$	173,013	$	156,991