Consolidated Balance Sheets (unaudited) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 31,877	$ 23,551
Trade receivables, net	41,070	43,094
Inventories, net	74,066	71,221
Prepaid expenses and other current assets	8,727	6,104
Total current assets	155,740	143,970
Property, plant and equipment, net	155,735	151,815
Goodwill	36,426	37,312
Intangible assets, net	3,910	4,091
Investments in and advances to partially-owned affiliates	15,241	15,094
Deferred income taxes	37,588	39,262
Other non-current assets	5,878	2,924
Total assets	410,518	394,468
Current liabilities:
Accounts payable	25,725	27,612
Deferred revenue	12,055	11,570
Accrued expenses and other current liabilities	39,414	43,844
Total current liabilities	77,194	83,026
Long-term debt	73,000	64,000
Deferred income taxes	19,838	18,577
Accrued pension benefits	54,630	55,373
Other non-current liabilities	14,129	10,195
Total liabilities	238,791	231,171
Stockholders' equity:
Common stock, $.10 par value; authorized 100,000,000, issued 31,816,829 and 31,704,230 shares at respective dates	3,181	3,169
Additional paid-in capital	105,023	104,173
Retained earnings	116,431	105,263
Treasury stock, at cost, 1,790,873 and 1,795,082 shares at respective dates	(15,269)	(15,217)
Accumulated other comprehensive loss	(37,639)	(34,091)
Total stockholders' equity	171,727	163,297
Total liabilities and stockholders' equity	$ 410,518	$ 394,468