Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 183,727	$ 181,742
Accounts receivable, net	202,675	171,193
Inventories	136,519	133,906
Income taxes prepaid and receivable	6,266	5,213
Prepaid expenses and other current assets	14,520	9,251
Total current assets	543,707	501,305
Property, plant and equipment, net	454,302	422,564
Intangibles, net	55,441	66,454
Goodwill	166,796	160,375
Deferred income taxes	68,648	68,865
Contract receivables	32,811	14,045
Other assets	39,493	29,825
Total assets	1,361,198	1,263,433
Current liabilities:
Notes and loans payable	262	312
Accounts payable	44,899	43,305
Accrued liabilities	105,914	95,195
Current maturities of long-term debt	1,799	51,666
Income taxes payable	8,643	9,531
Total current liabilities	161,517	200,009
Long-term debt	514,120	432,918
Other noncurrent liabilities	101,555	106,827
Deferred taxes and other liabilities	10,991	12,389
Total liabilities	788,183	752,143
Shareholders' Equity
Preferred stock, par value $5.00 per share; authorized 2,000,000 shares; none issued
Additional paid-in capital	428,423	425,953
Retained earnings	534,082	522,855
Accumulated items of other comprehensive income:
Translation adjustments	(87,318)	(133,298)
Pension and postretirement liability adjustments	(50,536)	(51,719)
Derivative valuation adjustment	1,953	828
Treasury stock (Class A), at cost; 8,431,335 shares in 2017 and 8,443,444 shares in 2016	(256,876)	(257,136)
Total Company shareholders' equity	569,768	507,523
Noncontrolling interest	3,247	3,767
Total equity	573,015	511,290
Total liabilities and shareholders' equity	1,361,198	1,263,433
Common Class A [Member]
Shareholders' Equity
Common Stock	37	37
Common Class B [Member]
Shareholders' Equity
Common Stock	$ 3	$ 3