Inventories (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Gross inventories at FIFO [Abstract]
Finished goods	$ 26,751,000	$ 11,914,000
Work in progress	31,136,000	27,749,000
Raw materials & component parts	185,739,000	144,731,000
Maintenance, tooling & supplies	14,864,000	17,001,000
Total gross inventories at FIFO	258,490,000	201,395,000
Less reserves [Abstract]
LIFO	34,954,000	32,103,000
Valuation	5,061,000	3,144,000
Total inventories as reported	218,475,000	166,148,000
Gross inventories on FIFO basis accounted for on a LIFO basis	$ 120,700,000	$ 97,900,000