CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 11,843	$ 13,511
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	10,323	9,472
(Gain) loss on sales and/or abandonment of preperty and equipment	(6)	4
Write-off of patents	10	17
Acquired in-process research and development	2,175	0
Amortization of deferred credits	(114)	(54)
Realized gain on sale of marketable securities	(648)	0
Deferred income taxes	20	106
Changes in fair value of contingent consideration liability related to acquisitions	460	0
Tax benefit attributable to appreciation of common stock options exercised	(166)	(2,854)
Stock-based compensation expense	1,025	646
Changes in operating assets and liabilities, net of effects from acquisitions:
Trade receivables	(7,387)	(4,138)
Employee receivables	(23)	(39)
Other receivables	(594)	(115)
Inventories	(1,091)	(2,126)
Prepaid expenses	(309)	(1,836)
Prepaid income taxes	(29)	(8)
Income tax refund receivable	281	(178)
Other assets	(437)	(391)
Trade payables	3,582	(2,817)
Accrued expenses	365	318
Advances from employees	35	(125)
Income taxes payable	1,966	5,297
Liabilities related to unrecognized tax benefits	(167)	0
Deferred compensation payable	432	410
Other long-term obligations	16	416
Total adjustments	9,719	2,005
Net cash provided by operating activities	21,562	15,516
Capital expenditures for:
Property and equipment	(34,746)	(23,551)
Patents and trademarks	(813)	(1,351)
Proceeds from the sale of marketable securities	2,105	0
Proceeds from the sale of property and equipment	9	0
Cash paid in acquisitions	(14,770)	(1,500)
Net cash used in investing activities	(48,215)	(26,402)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock	536	94,798
Borrowings under long-term debt	94,801	18,598
Payments on long-term debt	(68,919)	(45,135)
Excess tax benefits from stock-based compensation	166	2,854
Contingent payments related to acquisitions	(12)	0
Payment of taxes related to an exchange of common stock	(80)	(819)
Net cash provided by financing activities	26,492	70,296
EFFECT OF EXCHANGE RATES ON CASH	(49)	(136)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(210)	59,274
CASH AND CASH EQUIVALENTS:
Beginning of period	10,128	3,735
End of period	9,918	63,009
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION-Cash paid during the period for:
Interest (net of capitalized interest of $170 and $240, respectively)	233	665
Income taxes	2,903	2,060
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING ACTIVITIES
Property and equipment purchases in accounts payable	6,763	5,432
Acquisition purchases in other payables, accrued expenses and other long-term obligations	11,500	4,000
Merit common stock surrendered (25 and 103 shares, respectively) in exchange for exercise of stock options	340	1,732
Equity offering cost in accrued expenses	$ 0	$ 127