CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating activities
Net income (loss)	$ 71,517	$ 26,752	$ (22,722)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Amortization expense	67,181	60,680	14,752
Depreciation expense	1,736	870	731
Deferred income taxes	(78,042)
Stock-based compensation expense	24,255	21,910	16,528
Non-cash lease expense	18	57	313
Non-cash interest expense for amortization of debt discount and issuance costs	3,406	8,972
Changes in operating assets and liabilities:
Accounts receivable	(22,524)	(10,367)	4,993
Inventory	(2,296)	(8,270)	(1,826)
Prepaid expenses and other assets	(1,086)	(1,598)	2,037
Accounts payable	(5,827)	3,769	(5,903)
Accrued expenses	4,777	(7,838)	6,056
Accrued rebates, returns and discounts	40,442	(995)	12,766
Operating lease assets and liabilities			734
Other long-term liabilities			(676)
Net cash provided by operating activities	103,557	93,942	27,783
Investing activities
Purchase of intangible asset		(368,226)
Purchases of property and equipment	(1,944)	(5,546)	(6,438)
Net cash used in investing activities	(1,944)	(373,772)	(6,438)
Financing activities
Proceeds from issuances of common stock from employee stock purchase plans	755	758	817
Proceeds from the exercise of stock options	11,952	6,577	2,046
Payments made for employee stock tax withholdings	(4,149)	(2,255)	(822)
Repurchases of common stock, including the ASR agreement	(47,861)
Proceeds from issuance of term note, net of issuance costs of $2,456		192,117
Proceeds from convertible senior notes, net of issuance costs of $5,473		138,277
Repayment of term notes	(50,000)	(37,500)
Repayment of term loan		(11,500)
Net cash (used in) provided by financing activities	(89,303)	286,474	2,041
Net increase in cash, cash equivalents and restricted cash	12,310	6,644	23,386
Cash, cash equivalents and restricted cash at beginning of period	176,663	170,019	146,633
Cash, cash equivalents and restricted cash at end of period	188,973	176,663	170,019
Reconciliation of cash, cash equivalents and restricted cash to the Consolidated Balance Sheets:
Cash and cash equivalents	186,426	174,116	170,019
Restricted cash	2,547	2,547
Total cash, cash equivalents and restricted cash	188,973	176,663	170,019
Supplemental disclosure of cash flow information
Cash paid for offering costs			30
Cash paid for interest	17,608	18,967	709
Cash paid for income taxes	3,005	483
Supplemental disclosure of non-cash activities
Acquisition of property and equipment in accounts payable and accrued expenses	72	293	134
Accrued royalties discharged upon closing of asset acquisition		1,145
Inventory used in the construction and installation of property and equipment	$ 516	2,299
Receivable from stock option exercises in other current assets		$ 80
Operating lease assets assumed			9,957
Operating lease liabilities assumed			$ 10,691