CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 5,451	$ 42,017	$ 27,523
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	92,100	69,546	53,582
Gain on bargain purchase			(11,039)
Loss on sales and/or abandonment of property and equipment	115	625	427
Write-off of certain intangible assets and other long-term assets	25,563	814	988
Acquired in-process research and development	525	644	12,136
Amortization of right-of-use operating lease assets	12,256
Amortization of deferred credits	(139)	(142)	(147)
Amortization of long-term debt issuance costs	721	804	685
Deferred income taxes	(12,436)	2,052	(1,304)
Stock-based compensation expense	9,382	6,117	4,075
Changes in operating assets and liabilities, net of effects from acquisitions:
Trade receivables	(17,900)	(27,522)	(12,844)
Other receivables	1,859	(2,754)	(3,557)
Inventories	(27,044)	(28,172)	(17,834)
Prepaid expenses and other current assets	(1,239)	(2,000)	(1,236)
Prepaid income taxes	128	(444)	(611)
Income tax refund receivables	(2,247)	232	(588)
Other assets	(5,141)	315	(3,735)
Trade payables	(2,295)	15,726	417
Accrued expenses	9,580	12,706	6,461
Income taxes payable	(351)	918	21
Long-term income taxes payable	(45)	(4,454)	4,846
Liabilities related to unrecognized tax benefits	(794)	267	(19)
Deferred compensation payable	3,635	39	1,970
Operating lease liabilities	(11,970)
Other long-term obligations	(1,901)	(801)	2,510
Total adjustments	72,362	44,516	35,204
Net cash provided by operating activities	77,813	86,533	62,727
Capital expenditures for:
Property and equipment	(78,173)	(63,324)	(38,623)
Intangible assets	(3,324)	(3,012)	(2,577)
Proceeds from the sale of property and equipment	920	55	21
Issuance of note receivable		(10,750)
Cash paid in acquisitions, net of cash acquired	(53,904)	(301,789)	(105,582)
Net cash used in investing activities	(134,481)	(378,820)	(146,761)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock	6,252	214,993	143,810
Offering costs		(366)	(816)
Proceeds from issuance of long-term debt	246,659	639,108	197,214
Payments on long-term debt	(202,159)	(522,608)	(243,214)
Long-term debt issuance costs	(1,479)		(416)
Contingent payments related to acquisitions	(15,740)	(231)	(61)
Payment of taxes related to an exchange of common stock		(2,616)
Net cash provided by financing activities	33,533	328,280	96,517
EFFECT OF EXCHANGE RATES ON CASH	96	(970)	682
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(23,039)	35,023	13,165
CASH AND CASH EQUIVALENTS:
Beginning of period	67,359	32,336	19,171
End of period	44,320	67,359	32,336
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION
Interest (net of capitalized interest of $1,290, $647 and $513, respectively)	12,434	10,324	7,707
Income taxes	12,069	8,692	6,049
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING ACTIVITIES
Property and equipment purchases in accounts payable	7,952	4,989	1,992
Receivable for issuance of common stock associated with option exercises			137
Acquisition purchases in accrued expenses and other long-term obligations	10,541	72,209	$ 10,488
Merit common stock surrendered (3, 43, and 0 shares, respectively) in exchange for exercise of stock options	93	$ 2,261
Right-of-use operating lease assets obtained in exchange for operating lease liabilities	$ 10,637