Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities:
Net income	$ 29,040	$ 25,196
Adjustments to reconcile net income to net cash from operating activities:
Provision for credit losses on accounts receivable	150	965
Reserve for product returns	1,129	1,000
Recovery of credit losses on notes receivable	(11)	(382)
Amortization on patents and tooling	603	401
Amortization and depreciation	14,862	13,145
Amortization of debt discount and debt issuance costs	7,399	54
Amortization of operating leases	4,695	4,234
Deferred income taxes	(7,143)	(2,526)
Change in fair value of contingent liability	0	(2,289)
Stock-based compensation	17,944	13,453
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	(10,565)	(2,549)
Inventory	(15,330)	(16,238)
Other current and non-current assets	(8,131)	(3,270)
Accounts payable, accrued expenses and other current liabilities	13,403	17,332
Deferred revenue	2,490	1,039
Operating lease liabilities	(5,677)	(4,728)
Other liabilities	265	(86)
Cash flows from operating activities	45,308	48,048
Cash flows used in investing activities:
Additions to property and equipment	(7,381)	(7,116)
Purchases of in-process research and development	0	(3,297)
Receipt of payments on notes receivable	5	2,007
Purchase of investment in unconsolidated entity	(5,000)	0
Purchases of patents and patent licenses	0	(900)
Cash flows used in investing activities	(12,376)	(9,306)
Cash flows from financing activities:
Proceeds from credit facility	0	50,000
Repayments of credit facility	(110,000)	(1,000)
Proceeds from issuance of convertible senior notes	500,000	0
Payments of debt issuance costs	(15,698)	0
Payments of deferred consideration for business acquisitions	(878)	(819)
Purchases of treasury stock	0	(5,149)
Issuances of common stock from equity-based plans	2,867	4,424
Cash flows from financing activities	376,291	47,456
Net increase in cash and cash equivalents	409,223	86,198
Cash and cash equivalents at beginning of the period	253,459	119,629
Cash and cash equivalents at end of the period	$ 662,682	$ 205,827