CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 47,874	$ 49,237
Accounts receivable, less allowances (2019 - $1,477; 2018 - $1,440)	156,349	144,938
Contract assets	22,322	23,040
Inventories	91,048	84,465
Taxes receivable	3,138	2,912
Prepaid expenses	5,062	4,707
Other current assets	8,669	7,779
Total current assets	334,462	317,078
Property, plant and equipment, at cost	462,765	458,075
Accumulated depreciation	(248,845)	(244,706)
Net, property, plant and equipment	213,920	213,369
Operating lease right-of-use assets	27,254	0
Goodwill	197,022	196,963
Other intangible assets, net	131,325	136,604
Other assets, net	7,929	8,672
Total assets	911,912	872,686
Current liabilities:
Current portion of long-term debt	10,111	10,172
Accounts payable	86,921	73,265
Accrued payroll and other compensation	18,724	16,621
Deferred revenue	5,471	6,990
Other accrued liabilities	21,571	14,298
Total current liabilities	142,798	121,346
Long-term debt	307,656	314,641
Long-term operating lease liabilities	22,138	0
Deferred tax liabilities	39,038	39,265
Benefit plan liabilities	22,170	22,795
Other long-term liabilities	4,898	5,364
Commitments and Contingencies (Note 16)
Stockholders’ equity:
Preferred stock	0	0
Common stock	252	253
Capital in excess of par value	91,713	90,851
Retained earnings	415,032	411,325
Accumulated other comprehensive loss	(43,272)	(42,685)
Treasury stock, at cost	(90,511)	(90,469)
Total stockholders’ equity	373,214	369,275
Total liabilities and stockholders’ equity	$ 911,912	$ 872,686