Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities:
Net income	$ 8,332	$ 5,767
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	4,050	3,874
Gain on sale of fixed assets		(55)
Share-based compensation	696	691
Deferred income taxes	837	688
Changes in operating assets and liabilities:
Receivables, net	(2,360)	(4,414)
Inventories	538	(1,451)
Prepaid expenses	(61)	(149)
Refundable income taxes	1,568	401
Other assets	(178)	(248)
Accounts payable	(1,222)	2,907
Accrued expenses	30	(1,005)
Deferred revenue	444	286
Non-qualified deferred compensation plan and other liabilities	(316)	155
Net cash provided by operating activities	12,358	7,447
Cash flows from investing activities:
Additions to property, plant, and equipment	(2,819)	(2,991)
Acquisition of Dielectrics, net of cash acquired		(76,978)
Proceeds from sale of fixed assets		68
Net cash used in investing activities	(2,819)	(79,901)
Cash flows from financing activities:
Proceeds from advances on revolving line of credit		36,000
Payments on revolving line of credit	(7,000)	(15,000)
Proceeds from the issuance of long-term debt		20,000
Principal repayments of long-term debt	(715)	(1,429)
Proceeds from exercise of stock options, net of shares presented for exercise	440	964
Payment of statutory withholdings for stock options exercised and restricted stock units vested	(271)	(144)
Net cash (used in) provided by financing activities	(7,546)	40,391
Net increase (decrease) in cash and cash equivalents	1,993	(32,063)
Cash and cash equivalents at beginning of period	3,238	37,978
Cash and cash equivalents at end of period	$ 5,231	$ 5,915