Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net (loss) income	$ (95,304)	$ 68,271	$ (41,276)
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation and amortization	7,430	4,883	14,489
Impairment of intangible asset	66,087	0	0
Amortization of premiums on marketable securities	2,823	732	918
Remeasurement of related party acquisition-related contingent consideration	(22,731)	(31,040)	49,285
Remeasurement of related party financing-related contingent consideration	(1,899)	(2,071)	6,548
Amortization of debt discount and debt issuance costs	4,830	0	0
Change in deferred tax and income tax deferred charge	(19,152)	3,556	(4,000)
Stock-based compensation expense	7,852	8,072	14,679
Other adjustments	1,365	(968)	(331)
Net changes in assets and liabilities
Accounts receivable	3,452	3,054	(10,050)
Inventories	711	(2,899)	1,831
Prepaid expenses and other current assets	3,577	(3,741)	3,412
Research and development tax credit receivable	(2,545)	(3,141)	397
Accounts payable & other current liabilities	(2,032)	595	(434)
Deferred revenue	(1,892)	(216)	(2,923)
Accrued expenses	(10,640)	13,187	6,764
Accrued income taxes	(341)	(786)	1,778
Earn-out payments for related party contingent consideration in excess of acquisition-date fair value	(19,468)	(31,636)	(20,252)
Royalty payments for related party payable in excess of original fair value	(2,838)	(4,429)	(2,469)
Other assets and liabilities	(2,001)	(4,761)	535
Net cash (used in) provided by operating activities	(82,716)	16,662	18,901
Cash flows from investing activities:
Purchases of property and equipment	(178)	(591)	(1,201)
Acquisitions of businesses, including cash acquired and other adjustments	0	0	628
Purchase of intangible assets	(20,000)	(53,111)	0
Proceeds from sales of marketable securities	359,507	189,009	71,546
Purchases of marketable securities	(376,310)	(151,005)	(107,603)
Net cash used in investing activities	(36,981)	(15,698)	(36,630)
Cash flows from financing activities:
Proceeds from debt issuance	143,750	0	0
Payments for debt issuance costs	(6,190)	0	0
Earn-out payments for related party contingent consideration	(645)	(1,246)	(6,892)
Royalty payments for related party payable	0	0	(1,225)
Exercise of warrants	2,911	0	0
Proceeds from issuance of ordinary shares and warrants	577	404	440
Share repurchases	(27,637)	(22,361)	0
Other financing activities, net	(107)	(115)	(277)
Net cash provided by (used in) financing activities	112,659	(23,318)	(7,954)
Effect of foreign currency exchange rate changes on cash and cash equivalents	(201)	(297)	(166)
Net change in cash and cash equivalents	(7,239)	(22,651)	(25,849)
Cash and cash equivalents at January 1	16,564	39,215	65,064
Cash and cash equivalents at December 31	9,325	16,564	39,215
Supplemental disclosures of cash flow information:
Income tax paid	776	19,143	27,180
Interest paid	$ 3,359	$ 1,050	$ 788