Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities
Net earnings	$ 113,056	$ 110,993	$ 57,284
Adjustments to reconcile net earnings to net cash provided by operating activities:
Loss on extinguishment of debt	0	0	295
Change in fair value of derivative liability	0	0	(76)
Depreciation and amortization	6,659	7,063	8,132
Noncash operating lease cost	3,566	0	0
Amortization of deferred financing costs and debt discount	15,708	11,848	50
Amortization of premium/discount on marketable securities	(4,335)	(1,665)	(563)
Noncash interest expense	5,775	4,271	1,434
Noncash royalty revenue	(6,927)	(5,914)	(5,283)
Share-based compensation expense	14,846	11,291	8,433
Deferred income tax (benefit) provision	(5,832)	(4,167)	21,224
Changes in operating assets and liabilities:
Accounts receivable	15,751	(35,856)	(24,059)
Inventories	(969)	(9,355)	497
Prepaid expenses and other current assets	(2,723)	(2,367)	(3,566)
Other noncurrent assets	(141)	0	0
Accounts payable	6,962	(3,578)	(620)
Accrued product returns and rebates	566	38,720	26,400
Accrued expenses and other current liabilities	(3,811)	10,432	2,888
Income taxes payable	(9,934)	(3,561)	15,931
Deferred licensing revenue	0	0	(274)
Other liabilities	(5,088)	831	6,513
Net cash provided by operating activities	143,129	128,986	114,640
Cash flows from investing activities
Purchases of marketable securities	(409,707)	(491,654)	(101,889)
Sales and maturities of marketable securities	253,170	79,827	28,657
Purchases of property and equipment	(2,736)	(844)	(2,029)
Deferred legal fees	1,349
Deferred legal fees		(809)	(11,154)
Net cash used in investing activities	(157,924)	(413,480)	(86,415)
Cash flows from financing activities
Proceeds from issuance of convertible notes	0	402,500	0
Convertible notes issuance financing costs	0	(10,435)	0
Proceeds from issuance of warrants	0	65,688	0
Purchases of convertible note hedges	0	(92,897)	0
Proceeds from issuance of common stock	3,928	11,582	5,681
Net cash provided by financing activities	3,928	376,438	5,681
Net change in cash and cash equivalents	(10,867)	91,944	33,906
Cash and cash equivalents at beginning of year	192,248	100,304	66,398
Cash and cash equivalents at end of period	181,381	192,248	100,304
Supplemental cash flow information:
Cash paid for interest on convertible notes	2,516	1,342	134
Income taxes paid	51,540	34,772	1,588
Noncash investing and financing activity:
Conversion of convertible notes and interest make-whole	0	0	4,548
Deferred legal fees and fixed assets included in accounts payable and accrued expenses	1,832	250	521
Unsettled purchase of marketable securities included in accrued expenses	0	0	1,004
Property and equipment additions from utilization of tenant improvement allowance	10,151	0	0
Acquisition of Biscayne Neurotherapeutics, Inc.
Supplemental cash flow information:
Cash paid for Biscayne acquisition	$ 0	$ 15,000	$ 0