CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current Assets:
Cash and cash equivalents	$ 54,296	$ 69,354
Accounts receivable, net of allowance for doubtful accounts of $2,191 in 2018 and $1,745 in 2017	97,577	78,808
Unbilled receivables	16,553	0
Inventories	114,434	107,719
Other current assets	9,626	10,218
Total current assets	292,486	266,099
Property, plant and equipment, net	42,994	43,495
Intangible assets, net	64,161	69,366
Goodwill	19,135	20,177
Deferred income taxes	2,083	4,155
Other assets	27,044	27,973
Total assets	447,903	431,265
Current Liabilities:
Accounts payable	62,415	47,947
Accrued expenses	32,533	30,508
Current portion of long-term debt	2,507	2,641
Other current liabilities	3,836	6,204
Total current liabilities	101,291	87,300
Long-term Liabilities:
Long-term debt	112,331	120,053
Liability for uncertain tax positions	27,180	27,948
Minimum pension obligation and unfunded pension liability	19,943	19,134
Deferred income taxes	1,472	1,567
Other liabilities	12,375	17,303
Total liabilities	274,592	273,305
Commitments and contingencies
Stockholders' Equity:
Preferred stock, no par value, 1,000,000 shares authorized; none issued	0	0
Additional paid-in capital	30,602	28,575
Retained earnings	165,518	147,807
Accumulated other comprehensive loss	(24,033)	(19,625)
Total stockholders' equity	173,311	157,960
Total liabilities and stockholders' equity	447,903	431,265
Class A Common Stock [Member]
Stockholders' Equity:
Common Stock	217	217
Class B Common Stock [Member]
Stockholders' Equity:
Common Stock	$ 1,007	$ 986