CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 16,210	$ 24,286
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	32,779	25,709
Gain on bargain purchase	0	(11,574)
Loss on sales and/or abandonment of property and equipment	371	234
Write-off of patents and intangible assets	86	19
Acquired in-process research and development	306	75
Amortization of deferred credits	(71)	(76)
Amortization of long-term debt issuance costs	402	343
Deferred income taxes	0	(295)
Stock-based compensation expense	2,821	1,691
Changes in operating assets and liabilities, net of effects from acquisitions:
Trade receivables	(27,947)	(13,248)
Other receivables	966	(114)
Inventories	(7,189)	(2,160)
Prepaid expenses and other current assets	(3,105)	(1,230)
Prepaid income taxes	(100)	(92)
Income tax refund receivables	(1,146)	294
Other assets	(751)	(1,500)
Trade payables	15,767	3,664
Accrued expenses	7,467	7,421
Income taxes payable	(2,076)	(301)
Deferred compensation payable	438	513
Other long-term obligations	(179)	907
Total adjustments	18,839	10,280
Net cash provided by operating activities	35,049	34,566
Capital expenditures for:
Property and equipment	(31,559)	(17,782)
Intangible assets	(1,755)	(1,082)
Proceeds from the sale of property and equipment	4	3
Issuance of note receivable	(10,500)	0
Cash paid in acquisitions, net of cash acquired	(118,654)	(54,809)
Net cash used in investing activities	(162,464)	(73,670)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock	3,251	140,989
Offering costs	0	(815)
Proceeds from issuance of long-term debt	320,827	96,859
Payments on long-term debt	(185,827)	(179,359)
Contingent payments related to acquisitions	(130)	(30)
Net cash provided by financing activities	138,121	57,644
EFFECT OF EXCHANGE RATES ON CASH	470	(36)
NET INCREASE IN CASH AND CASH EQUIVALENTS	11,176	18,504
CASH AND CASH EQUIVALENTS:
Beginning of period	32,336	19,171
End of period	43,512	37,675
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION
Interest (net of capitalized interest of $314 and $240, respectively)	5,714	4,386
Income taxes	5,141	2,678
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING ACTIVITIES
Property and equipment purchases in accounts payable	3,943	1,560
Acquisition purchases in accrued expenses and other long-term obligations	0	6,000
Merit common stock surrendered (32 and 0 shares, respectively) in exchange for exercise of stock options	$ 1,684	$ 0