CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 92,546	$ 51,331
Accounts receivable, net of allowance for doubtful accounts of $2,647 and $1,842, respectively	100,767	107,786
Contract assets	27,969	28,245
Inventories	80,300	80,544
Taxes receivable	2,235	3,427
Prepaid expenses	4,389	3,814
Other current assets	8,562	8,450
Total current assets	316,768	283,597
Property, plant and equipment, at cost	483,013	487,371
Accumulated depreciation	(276,577)	(265,729)
Property, plant and equipment, net	206,436	221,642
Operating lease right-of-use assets	21,392	23,116
Goodwill	83,951	133,912
Other intangible assets, net	104,595	115,577
Other assets, net	7,391	8,093
Total assets	740,533	785,937
Current liabilities:
Current portion of long-term debt	9,855	9,928
Accounts payable	78,108	73,426
Accrued payroll and other compensation	20,130	17,198
Accrued taxes	11,152	5,638
Other accrued liabilities	25,106	23,668
Total current liabilities	144,351	129,858
Long-term debt	275,655	262,713
Long-term operating lease liabilities	17,157	18,424
Deferred tax liabilities	28,327	34,561
Benefit plan liabilities	18,528	18,957
Other long-term liabilities	3,253	3,004
Commitments and Contingencies (Note 15)
Stockholders’ equity:
Preferred stock	0	0
Common stock	255	253
Capital in excess of par value	95,985	94,140
Retained earnings	278,351	340,629
Accumulated other comprehensive loss	(30,698)	(25,979)
Treasury stock, at cost	(90,631)	(90,623)
Total stockholders’ equity	253,262	318,420
Total liabilities and stockholders’ equity	740,533	785,937
Allowances of accounts receivable	$ 2,647	$ 1,842