Consolidated Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 13,138,000	$ 10,197,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	4,081,000	3,602,000
Realized gain on foreign currency exchange rate		(264,000)
Provision for bad debts - accounts receivable	814,000	410,000
Share-based compensation expense	1,654,000	1,595,000
Deferred income tax benefit	(586,000)	(2,141,000)
Gain on sale of property, plant and equipment	(1,018,000)
Accretion of acquisition-related contingent liabilities	115,000	126,000
Changes in assets and liabilities, net of acquisition of business:
Accounts receivable - trade	(1,746,000)	(6,656,000)
Accounts receivable - other	931,000	417,000
Inventories	3,270,000	(1,900,000)
Prepaid expenses and other current assets	(189,000)	(1,281,000)
Other assets	(2,756,000)	(100,000)
Accounts payable	129,000	1,374,000
Other current liabilities	(854,000)	718,000
Long-term pension liability	(529,000)	570,000
Other long-term liabilities	977,000	(20,000)
Net cash provided by operating activities	17,431,000	6,647,000
CASH FLOWS FROM INVESTING ACTIVITIES
Additions to property, plant and equipment	(2,518,000)	(6,596,000)
Proceeds from disposals of property, plant and equipment	2,858,000
Purchase of businesses, net of acquired cash	(766,000)	(15,161,000)
Net cash used in investing activities	(426,000)	(21,757,000)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from long-term debt	72,543,000	108,175,000
Repayment of long-term debt	(75,707,000)	(87,620,000)
Payment of cash dividends	(3,874,000)	(3,487,000)
Payment of contingent liabilities	(1,800,000)	(1,800,000)
Proceeds received on exercise of stock options	1,218,000	1,109,000
Tax withholding on exercise of stock rights	(421,000)	(268,000)
Common stock reacquired and retired		(316,000)
Net cash (used in) provided by financing activities	(7,391,000)	16,783,000
Effect of currency exchange rates on cash	46,000	91,000
Net increase in cash and cash equivalents	9,660,000	1,764,000
Cash and cash equivalents balance, beginning of year	3,649,000	1,036,000
Cash and cash equivalents balance, end of period	13,309,000	2,800,000
Restricted Stock [Member]
CASH FLOWS FROM FINANCING ACTIVITIES
Tax benefit from vesting of acquisition related restricted stock	$ 650,000	$ 990,000