CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ (9,843)	$ 5,451	$ 42,017
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	94,070	92,100	69,546
Gain on sale of business	(517)
Loss on sales and/or abandonment of property and equipment	2,159	115	625
Write-off of certain intangible assets and other long-term assets	36,609	25,563	814
Acquired in-process research and development	250	525	644
Amortization of right-of-use operating lease assets	12,746	12,256
Fair value adjustments to contingent consideration	(7,960)	(232)	(698)
Amortization of deferred credits	(130)	(139)	(142)
Amortization of long-term debt issuance costs	604	721	804
Deferred income taxes	(11,295)	(12,436)	2,052
Stock-based compensation expense	14,339	9,382	6,117
Changes in operating assets and liabilities, net of acquisitions and divestitures:
Trade receivables	10,425	(17,900)	(27,522)
Other receivables	1,668	1,787	(2,588)
Inventories	29,429	(27,044)	(28,172)
Prepaid expenses and other current assets	(446)	(1,239)	(2,000)
Prepaid income taxes	(162)	128	(444)
Income tax refund receivables	(339)	(2,247)	232
Other assets	(3,511)	(5,141)	149
Trade payables	333	(2,295)	15,726
Accrued expenses	4,603	4,719	12,623
Income taxes payable	(86)	(351)	918
Long-term income taxes payable		(45)	(4,454)
Liabilities related to unrecognized tax benefits	(576)	(794)	267
Deferred compensation payable	1,953	3,635	39
Operating lease liabilities	(12,659)	(11,970)
Other long-term obligations	3,606	3,264	(20)
Total adjustments	175,113	72,362	44,516
Net cash provided by operating activities	165,270	77,813	86,533
Capital expenditures for:
Property and equipment	(45,988)	(78,173)	(63,324)
Intangible assets	(3,288)	(3,324)	(3,012)
Proceeds from the sale of property and equipment	42	920	55
Proceeds from sale of business	1,285
Cash received for settlement of current note receivable	250
Issuance of note receivable			(10,750)
Cash paid in acquisitions, net of cash acquired	(10,953)	(53,904)	(301,789)
Net cash used in investing activities	(58,652)	(134,481)	(378,820)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock	6,635	6,252	214,993
Offering costs			(366)
Proceeds from issuance of long-term debt	68,625	246,659	639,108
Payments on long-term debt	(157,000)	(202,159)	(522,608)
Long-term debt issuance costs		(1,479)
Contingent payments related to acquisitions	(13,100)	(15,740)	(231)
Payment of taxes related to an exchange of common stock	(866)		(2,616)
Net cash provided by (used in) financing activities	(95,706)	33,533	328,280
EFFECT OF EXCHANGE RATES ON CASH	1,684	96	(970)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	12,596	(23,039)	35,023
CASH AND CASH EQUIVALENTS:
Beginning of period	44,320	67,359	32,336
End of period	56,916	44,320	67,359
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION
Interest (net of capitalized interest of $813, $1,290 and $647, respectively)	10,077	12,434	10,324
Income taxes	8,918	12,069	8,692
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING ACTIVITIES
Property and equipment purchases in accounts payable	2,180	7,952	4,989
Current note receivable converted to equity investment	899
Proceeds from sale of business in other receivables	321
Acquisition purchases in accrued expenses and other long-term obligations	4,358	10,541	72,209
Merit common stock surrendered (39, 3 and 43 shares, respectively) in exchange for exercise of stock options	1,467	93	$ 2,261
Right-of-use operating lease assets obtained in exchange for operating lease liabilities	$ 10,938	$ 10,637