CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 19,069	$ 18,074
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	16,724	14,250
(Gain) loss on sales and/or abandonment of preperty and equipment	(1)	3
Write-off of patents	27	59
Acquired in-process research and development	2,450	3,438
Amortization of deferred credits	(140)	(81)
Realized gain on sale of marketable securities	(745)	0
Deferred income taxes	14	463
Changes in fair value of contingent consideration liability related to acquisitions	370	0
Tax benefit attributable to appreciation of common stock options exercised	(716)	(2,857)
Stock-based compensation expense	1,454	1,082
Changes in operating assets and liabilities, net of effects from acquisitions:
Trade receivables	(7,521)	(3,191)
Employee receivables	(78)	(88)
Other receivables	(490)	(204)
Inventories	(8,884)	(5,960)
Prepaid expenses	(598)	(1,755)
Prepaid income taxes	2	(2)
Income tax refund receivable	259	(367)
Other assets	(869)	(87)
Trade payables	5,805	(2,320)
Accrued expenses	2,793	2,606
Advances from employees	408	501
Income taxes payable	2,670	6,568
Liabilities related to unrecognized tax benefits	(993)	(823)
Deferred compensation payable	838	124
Other long-term obligations	314	976
Total adjustments	13,093	12,335
Net cash provided by operating activities	32,162	30,409
Capital expenditures for:
Property and equipment	(49,264)	(38,787)
Patents and trademarks	(1,059)	(1,768)
Proceeds from the sale of marketable securities	3,248	0
Proceeds from the sale of property and equipment	9	5
Cash paid in acquisitions	(23,555)	(8,250)
Net cash used in investing activities	(70,621)	(48,800)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock	3,326	94,800
Borrowings under long-term debt	127,914	61,507
Payments on long-term debt	(94,151)	(137,426)
Excess tax benefits from stock-based compensation	716	2,857
Proceeds from industrial assistant grants	324	0
Contingent payments related to acquisitions	(36)	0
Payment of taxes related to an exchange of common stock	(287)	(819)
Net cash provided by financing activities	37,806	20,919
EFFECT OF EXCHANGE RATES ON CASH	(10)	(444)
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(663)	2,084
CASH AND CASH EQUIVALENTS:
Beginning of period	10,128	3,735
End of period	9,465	5,819
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION-Cash paid during the period for:
Interest (net of capitalized interest of $289 and $264, respectively)	238	749
Income taxes	4,629	3,192
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING ACTIVITIES
Property and equipment purchases in accounts payable	7,429	7,065
Acquisition purchases in accrued expenses and other long-term obligations	5,000	2,208
Acquisition of customer list in exchange for a settlement of trade receivables	378	0
Merit common stock surrendered (71 and 103 shares, respectively) in exchange for exercise of stock options	$ 1,032	$ 1,732