CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ 10,958	$ (3,154)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	21,400	23,320
Loss on sales and/or abandonment of property and equipment	(28)	37
Write-off of certain intangible assets and other long-term assets		3,925
Amortization of right-of-use operating lease assets	3,070	3,134
Fair value adjustments to contingent consideration	402	4,897
Amortization of deferred credits	(27)	(35)
Amortization of long-term debt issuance costs	151	151
Stock-based compensation expense	3,595	2,777
Changes in operating assets and liabilities, net of acquisitions and divestitures:
Trade receivables	(5,284)	3,445
Other receivables	(597)	613
Inventories	(3,396)	(4,983)
Prepaid expenses and other current assets	(1,071)	(3,126)
Income tax refund receivables	199	(2,475)
Other assets	80	(577)
Trade payables	4,237	4,340
Accrued expenses	5,393	(1,621)
Income taxes payable	(174)	2,109
Deferred compensation payable	(581)	(789)
Operating lease liabilities	(3,151)	(2,945)
Other long-term obligations	56	(179)
Total adjustments	24,274	32,018
Net cash provided by operating activities	35,232	28,864
Capital expenditures for:
Property and equipment	(6,171)	(13,950)
Intangible assets	(692)	(1,062)
Proceeds from the sale of property and equipment	873
Cash received for settlement of current note receivable		250
Cash paid in acquisitions, net of cash acquired	(358)
Net cash used in investing activities	(6,348)	(14,762)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock	5,520	1,261
Proceeds from issuance of long-term debt	9,694	30,665
Payments on long-term debt	(40,569)	(24,540)
Contingent payments related to acquisitions	(403)	(12,754)
Payment of taxes related to an exchange of common stock	(488)	(866)
Net cash used in financing activities	(26,246)	(6,234)
EFFECT OF EXCHANGE RATES ON CASH	(1,035)	(2,108)
NET INCREASE IN CASH AND CASH EQUIVALENTS	1,603	5,760
CASH AND CASH EQUIVALENTS:
Beginning of period	56,916	44,320
End of period	58,519	50,080
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION
Interest (net of capitalized interest of $120 and $392, respectively)	1,539	3,198
Income taxes	1,660	1,637
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING ACTIVITIES
Property and equipment purchases in accounts payable	1,688	5,383
Current note receivable converted to equity investment		899
Merit common stock surrendered (2 and 39 shares, respectively) in exchange for exercise of stock options	93	1,467
Right-of-use operating lease assets obtained in exchange for operating lease liabilities	$ 131	$ 2,800