Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
OPERATING ACTIVITIES:
Net income	$ 107,889	$ 26,114
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and other	24,366	24,458
Stock-based compensation expense	9,008	6,960
Amortization of debt discount and deferred issuance costs	433	1,151
Change in fair value of acquisition contingencies	848	626
Accretion of interest on deferred consideration	3,612	4,504
Change in deferred tax assets and liabilities	(21)	0
Change in fair value of derivative liabilities - Convertible Senior Notes	1,084	0
Loss on extinguishment of debt	0	748
Changes in assets and liabilities:
Accounts receivable	(16,450)	13,997
Inventories	(34,501)	2,704
Prepaid expenses and other current and non-current assets	(3,791)	2,139
Accounts payable	9,414	(808)
Accrued payroll and related expenses	4,974	(4,037)
Other current and non-current liabilities	13,312	(5,125)
Net cash provided by operating activities:	120,177	73,431
INVESTING ACTIVITIES:
Acquisitions of property, equipment and intangibles	(13,388)	(11,784)
Net cash used for investing activities:	(13,388)	(11,784)
FINANCING ACTIVITIES:
Proceeds from issuance of common stock	6,091	8,233
Payments on Revolving Credit Facility	(228)	(157)
Payments on finance lease obligation	0	(35,000)
Repurchases of common stock	(44,848)	(1,871)
Payments of acquisition contingent consideration	(6,034)	(4,031)
Payments of deferred consideration	(42,000)	(44,000)
Net cash used for financing activities:	(87,019)	(76,826)
Effect of exchange rates on cash	44	38
Net increase (decrease) in cash and cash equivalents	19,814	(15,141)
Cash and cash equivalents, beginning of period	52,775	43,695
Cash and cash equivalents, end of period	72,589	28,554
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING TRANSACTIONS:
Initial measurement of derivative liabilities – Convertible Senior Notes	26,180	0
Purchase of property, equipment and intangibles by incurring current liabilities	2,175	1,351
Reduction of other current liabilities upon issuance of restricted share units	767	2,018
Extinguishment of Convertible Senior Notes through issuance of common stock	$ 48	$ 86,428