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 (loss) income	$ (33,226)	$ (95,304)	$ 68,271
Adjustments to reconcile net (loss) income to net cash (used in) provided by operating activities:
Depreciation and amortization	2,486	7,430	4,883
Impairment of intangible asset	0	66,087	0
Amortization of premiums on marketable securities	41	2,823	732
Remeasurement of related party acquisition-related contingent consideration	845	(22,731)	(31,040)
Remeasurement of related party financing-related contingent consideration	378	(1,899)	(2,071)
Amortization of debt discount and debt issuance costs	5,995	4,830	0
Changes in deferred tax	(6,334)	(19,152)	3,556
Share-based compensation expense	519	7,852	8,072
Loss on deconsolidation of subsidiary	1,750	0	0
Other adjustments	(295)	1,365	(968)
Net changes in assets and liabilities
Accounts receivable	2,471	3,452	3,054
Inventories, net	1,155	711	(2,899)
Prepaid expenses and other current assets	(1,187)	3,577	(3,741)
Research and development tax credit receivable	(1,014)	(2,545)	(3,141)
Accounts payable & other current liabilities	4,641	(2,032)	595
Deferred revenue	(114)	(1,892)	(216)
Accrued expenses	357	(10,640)	13,187
Accrued income taxes	(30)	(341)	(786)
Earn-out payments for related party contingent consideration in excess of acquisition-date fair value	(10,988)	(19,468)	(31,636)
Royalty payments for related party payable in excess of original fair value	(1,748)	(2,838)	(4,429)
Other assets and liabilities	(4,027)	(2,001)	(4,761)
Net cash (used in) provided by operating activities	(38,325)	(82,716)	16,662
Cash flows from investing activities:
Purchases of property and equipment	(29)	(178)	(591)
Proceeds from disposal of property and equipment	154	0	0
Purchase of intangible assets	0	(20,000)	(53,111)
Proceeds from sales of marketable securities	63,246	359,507	189,009
Purchases of marketable securities	(24,648)	(376,310)	(151,005)
Net cash provided by (used in) investing activities	38,723	(36,981)	(15,698)
Cash flows from financing activities:
Proceeds from debt issuance	0	143,750	0
Payments for debt issuance costs	0	(6,190)	0
Earn-out payments for related party contingent consideration	0	(645)	(1,246)
Exercise of warrants	0	2,911	0
Proceeds from issuance of ordinary shares	118	577	404
Share repurchases	0	(27,637)	(22,361)
Other financing activities, net	(145)	(107)	(115)
Net cash (used in) provided by financing activities	(27)	112,659	(23,318)
Effect of foreign currency exchange rate changes on cash and cash equivalents	78	(201)	(297)
Net change in cash and cash equivalents	449	(7,239)	(22,651)
Cash and cash equivalents at January 1	9,325	16,564	39,215
Cash and cash equivalents at December 31	9,774	9,325	16,564
Supplemental disclosures of cash flow information:
Income tax paid	140	776	19,143
Interest paid	$ 6,469	$ 3,359	$ 1,050