Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net income	$ 14,550	$ 8,571
Adjustments to reconcile net income to net cash from operating activities:
Provision for credit losses on accounts receivable	32	1,885
Reserve for product returns	574	291
Recovery of credit losses on notes receivable	(11)	(349)
Amortization on patents and tooling	288	199
Amortization and depreciation	7,385	6,422
Amortization of debt discount and debt issuance costs	3,250	27
Amortization of operating leases	2,338	2,045
Deferred income taxes	(3,178)	1,327
Change in fair value of contingent liability	0	(568)
Stock-based compensation	7,888	6,358
Acquired in-process research and development	0	3,297
Loss on early extinguishment of debt	185	0
Changes in operating assets and liabilities:
Accounts receivable	(5,685)	(8,064)
Inventory	(2,947)	(2,673)
Other current and non-current assets	(1,734)	(6,108)
Accounts payable, accrued expenses and other current liabilities	(220)	83
Deferred revenue	1,127	1,604
Operating lease liabilities	(2,772)	(2,259)
Other liabilities	162	812
Cash flows from operating activities	21,232	12,900
Cash flows used in investing activities:
Additions to property and equipment	(4,069)	(3,719)
Purchases of in-process research and development	0	(3,297)
Receipt of payments on notes receivable	2	3
Purchase of investment in unconsolidated entity	(5,000)	0
Cash flows used in investing activities	(9,067)	(7,013)
Cash flows from financing activities:
Proceeds from credit facility	0	50,000
Repayments of credit facility	(110,000)	0
Proceeds from issuance of convertible senior notes	500,000	0
Payments of debt issuance costs	(15,291)	0
Payments of deferred consideration for business acquisitions	(150)	0
Purchases of treasury stock	0	(5,149)
Issuances of common stock from equity-based plans	1,989	1,365
Cash flows from financing activities	376,548	46,216
Net increase in cash and cash equivalents	388,713	52,103
Cash and cash equivalents at beginning of the period	253,459	119,629
Cash and cash equivalents at end of the period	$ 642,172	$ 171,732