Consolidated Statements of Cash Flows (Unaudited) - USD ($)	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 8,176,000	$ 5,750,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	2,715,000	2,333,000
Provision for bad debts - accounts receivable	575,000	180,000
Share-based compensation expense	1,108,000	1,097,000
Deferred income tax benefit	(509,000)	(69,000)
Gain on sale of property, plant and equipment	(1,018,000)
Accretion of acquisition-related contingent liability	81,000	81,000
Changes in assets and liabilities, net of acquisition of business:
Accounts receivable - trade	552,000	(2,181,000)
Accounts receivable - other	674,000	1,125,000
Inventories	1,632,000	653,000
Prepaid expenses and other current assets	(1,353,000)	(1,648,000)
Other assets	(1,784,000)	(353,000)
Accounts payable	585,000	2,238,000
Other current liabilities	(2,808,000)	(1,464,000)
Long-term pension liability	(894,000)	259,000
Other long-term liabilities	829,000	40,000
Net cash provided by operating activities	8,561,000	8,041,000
CASH FLOWS FROM INVESTING ACTIVITIES
Additions to property, plant and equipment	(2,004,000)	(5,527,000)
Proceeds from disposals of property, plant and equipment	2,810,000
Purchase of business net of acquired cash		(15,252,000)
Net cash provided by (used in) investing activities	806,000	(20,779,000)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from long-term debt	72,422,000	90,514,000
Repayment of long-term debt	(74,088,000)	(71,138,000)
Payment of cash dividends	(2,490,000)	(2,270,000)
Payment of contingent liability	(1,800,000)	(1,800,000)
Proceeds received on exercise of stock options	798,000	781,000
Tax withholding on exercise of stock rights	(421,000)	(267,000)
Net cash (used in) provided by financing activities	(5,509,000)	16,355,000
Effect of currency exchange rates on cash	76,000	82,000
Net increase in cash and cash equivalents	3,934,000	3,699,000
Cash and cash equivalents balance, beginning of year	3,649,000	1,036,000
Cash and cash equivalents balance, end of period	7,583,000	4,735,000
Restricted Stock [Member]
CASH FLOWS FROM FINANCING ACTIVITIES
Tax benefit from vesting of acquisition related restricted stock	$ 70,000	$ 535,000