Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
OPERATING ACTIVITIES:
Net income	$ 340,157	$ 42,295
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and other	36,781	36,740
Stock-based compensation expense	14,561	10,084
Impairment loss	0	1,144
Amortization of debt discount and deferred issuance costs	615	1,367
Change in fair value of acquisition contingencies	848	626
Accretion of interest on deferred consideration	5,026	6,352
Change in deferred tax assets and liabilities	(441)	0
Change in fair value of derivative liabilities - Convertible Senior Notes	1,084	0
Loss on extinguishment of debt	10,384	748
Changes in assets and liabilities:
Accounts receivable	(258,216)	(19,344)
Inventories	(36,949)	5,395
Prepaid expenses and other current and non-current assets	(5,080)	4,942
Accounts payable	19,561	4,429
Accrued payroll and related expenses	10,078	(5,780)
Income taxes payable	51,814	(38)
Other current and non-current liabilities	409	(2,199)
Net cash provided by operating activities:	190,632	86,761
INVESTING ACTIVITIES:
Acquisitions of property, equipment and intangibles	(36,112)	(18,716)
Net cash used for investing activities:	(36,112)	(18,716)
FINANCING ACTIVITIES:
Proceeds from issuance of common stock	8,824	13,156
Payments on Revolving Credit Facility	0	(45,000)
Payments on finance lease obligation	353	262
Repurchases of common stock	(47,232)	(1,900)
Payments of acquisition contingent consideration	(6,043)	(4,044)
Payments of deferred consideration	(42,000)	(44,000)
Payments on convertible notes and derivative liability [Abstract]	(43,416)	0
Transaction costs related to debt exchange	0	(733)
Net cash used for financing activities:	(130,220)	(82,783)
Effect of exchange rates on cash	472	(43)
Net increase (decrease) in cash and cash equivalents	24,772	(14,781)
Cash and cash equivalents, beginning of period	52,775	43,695
Cash and cash equivalents, end of period	77,547	28,914
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING TRANSACTIONS:
Purchase of property, equipment and intangibles by incurring current liabilities	3,536	3,067
Reduction of other current liabilities upon issuance of restricted share units	767	2,018
Extinguishment of Convertible Senior Notes through issuance of common stock	$ 508	$ 86,428