CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Operating activities:
Net income	$ 29,450	$ 889
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Deferred taxes	7,613	0
Depreciation of fixed assets and amortization of intangible assets	9,748	9,810
Amortization of debt issuance costs	1,310	883
Amortization of debt discount	11,401	7,254
(Gain) loss on disposal and impairment of fixed assets	(10)	22
Stock-based compensation	20,571	18,070
Changes in contingent consideration	(988)	(2,312)
Loss (gain) on investment and other non-operating income, net	2,601	(8)
Changes in operating assets and liabilities:
Accounts receivable, net	(15,312)	3,517
Inventories, net	(615)	(8,394)
Prepaid expenses and other assets	(944)	(1,701)
Accounts payable	2,156	(3,517)
Accrued expenses and income taxes payable	(18,140)	(21,468)
Other liabilities	(964)	(3,052)
Payment of contingent consideration to MyoScience, Inc. securityholders	(5,662)	(9,409)
Net cash provided by (used in) operating activities	42,215	(9,416)
Investing activities:
Purchases of fixed assets	(23,624)	(15,630)
Purchases of available for sale investments	(318,132)	(72,263)
Sales of available for sale investments	294,288	95,450
Purchases of equity and debt investments	(14,220)	0
Sale of equity investment	9,057	0
Net cash (used in) provided by investing activities	(52,631)	7,557
Financing activities:
Proceeds from exercises of stock options	15,997	6,353
Proceeds from shares issued under employee stock purchase plan	1,574	1,421
Payment of contingent consideration to MyoScience, Inc. securityholders	(1,338)	(5,591)
Net cash provided by financing activities	16,233	2,183
Net increase in cash and cash equivalents	5,817	324
Cash and cash equivalents, beginning of period	99,957	78,228
Cash and cash equivalents, end of period	105,774	78,552
Supplemental cash flow information:
Cash paid for interest	3,586	4,097
Cash paid for income taxes, net of refunds	1,447	80
Non-cash investing and financing activities:
Fixed assets included in accounts payable and accrued liabilities	$ 8,096	$ 1,903