Inventories (Details) (USD $)	Dec. 31, 2011	Dec. 31, 2010
Gross inventories @ FIFO:
Finished goods	$ 11,914,000	$ 7,757,000
Work in progress	27,749,000	26,680,000
Raw materials & component parts	144,731,000	99,440,000
Maintenance, tooling & supplies	17,001,000	14,156,000
Total gross inventories @ FIFO	201,395,000	148,033,000
Less reserves:
LIFO	32,103,000	28,776,000
Valuation	3,144,000	2,383,000
Total inventories as reported	166,148,000	116,874,000
Gross inventories on FIFO basis accounted for on a LIFO basis	$ 97,900,000	$ 80,900,000