CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 6,539	$ 4,423
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	17,593	15,729
Losses (gains) on sales and/or abandonment of property and equipment	289	(10)
Write-off of patents	119	53
Amortization of deferred credits	(88)	(64)
Amortization of long-term debt issuance costs	494	399
Deferred income taxes	19	(6)
Excess tax benefits from stock-based compensation	(236)	(124)
Stock-based compensation expense	663	783
Changes in operating assets and liabilities, net of effects from acquisitions:
Trade receivables	(7,152)	(5,190)
Employee receivables	44	(27)
Other receivables	(753)	(463)
Inventories	(4,094)	3,039
Prepaid expenses	(366)	(669)
Prepaid income taxes	3	8
Income tax refund receivables	24	1,073
Other assets	(641)	(813)
Trade payables	2,299	586
Accrued expenses	3,539	(3,705)
Advances from employees	371	142
Income taxes payable	759	(1,319)
Liabilities related to unrecognized tax benefits	(264)	0
Deferred compensation payable	532	647
Other long-term obligations	446	(127)
Total adjustments	13,600	9,942
Net cash provided by operating activities	20,139	14,365
Capital expenditures for:
Property and equipment	(18,716)	(30,389)
Intangible assets	(925)	(661)
Proceeds from the sale of property and equipment	21	53
Cash paid in acquisitions, net of cash acquired	(1,450)	(1,000)
Net cash used in investing activities	(21,070)	(31,997)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock	3,528	876
Proceeds from issuance of long-term debt	71,734	71,172
Payments on long-term debt	(72,213)	(51,910)
Proceeds from industrial assistant grants	0	750
Excess tax benefits from stock-based compensation	236	124
Contingent payments related to acquisitions	(38)	(38)
Payment of taxes related to an exchange of common stock	(220)	(21)
Net cash provided by financing activities	3,027	20,953
EFFECT OF EXCHANGE RATES ON CASH	(154)	103
NET INCREASE IN CASH AND CASH EQUIVALENTS	1,942	3,424
CASH AND CASH EQUIVALENTS:
Beginning of period	7,459	9,719
End of period	9,401	13,143
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION
Interest (net of capitalized interest of $213 and $570, respectively)	4,969	2,970
Income taxes	1,911	1,071
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING ACTIVITIES
Property and equipment purchases in accounts payable	3,433	12,372
Merit common stock surrendered (108 and 45 shares, respectively) in exchange for exercise of stock options	$ 1,641	$ 452