Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
OPERATING ACTIVITIES:
Net income	$ 26,114	$ 30,882
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and other	24,458
Stock-based compensation expense	6,960	6,415
Amortization of debt discount and deferred issuance costs	1,151	2,714
Change in fair value of acquisition contingencies	626	745
Accretion of interest on deferred consideration	4,504	5,401
Amortization of inventory step-up to fair value	0	3,650
Loss on extinguishment of debt	748	6,965
Changes in assets and liabilities:
Accounts receivable	13,997	22,342
Inventories	2,704	3,710
Prepaid expenses and other current and non-current assets	2,139	(12,816)
Accounts payable	(808)	(5,070)
Accrued payroll and related expenses	(4,037)	(1,505)
Other current and non-current liabilities	(5,125)	(590)
Net cash provided by operating activities:	73,431	62,843
INVESTING ACTIVITIES:
Acquisitions of property and equipment	(11,784)	(13,577)
Proceeds from sale of Summers Ridge Property	0	146,644
Net cash (used for) provided by investing activities:	(11,784)	133,067
FINANCING ACTIVITIES:
Proceeds from issuance of common stock	8,233	9,549
Payments on Revolving Credit Facility	(157)	(60)
Payments on finance lease obligation	(35,000)	(10,000)
Repurchases of common stock	(1,871)	(3,607)
Payments of acquisition contingent consideration	(4,031)	(3,017)
Payments of deferred consideration	(44,000)	(46,000)
Payments of Term Loan	0	(161,813)
Transaction costs related to debt exchange	0	(2,002)
Net cash used for financing activities:	(76,826)	(216,950)
Effect of exchange rates on cash	38	10
Net (decrease) increase in cash and cash equivalents	(15,141)	(21,030)
Cash and cash equivalents, beginning of period	43,695	36,086
Cash and cash equivalents, end of period	28,554	15,056
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING TRANSACTIONS:
Purchase of property and equipment by incurring current liabilities	1,351	1,752
Reduction of other current liabilities upon issuance of restricted share units	2,018	0
Extinguishment of Convertible Senior Notes through issuance of common stock	$ 86,428	$ 200,185