Consolidated Statements of Changes in Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock/Ordinary Shares	Additional paid in capital	Accumulated other comprehensive income	Accumulated deficit	Total
Stockholders' equity, beginning balance at Dec. 31, 2016	$ 2,939	$ 279,149	$ 10	$ (204,842)	$ 77,256
Stockholders' equity, beginning balance (in shares) at Dec. 31, 2016	2,720
Consolidated Statements of Changes in Stockholders’ Equity
Issuance of ordinary shares	$ 94	79,906			80,000
Issuance of ordinary shares (in shares)	9,412
Exercise of stock options	$ 3	51			54
Exercise of stock options (in shares)	54
Equity transaction costs		(6,635)			(6,635)
Redomiciliation share exchange	$ (2,669)	2,669
Redomiciliation share exchange (in shares)	24,522
Stock-based compensation expense		5,732			5,732
Other comprehensive income, net of tax			17		17
Net loss				(74,356)	(74,356)
Stockholders' equity, ending balance at Dec. 31, 2017	$ 367	360,872	27	(279,198)	82,068
Stockholders' equity, ending balance (in shares) at Dec. 31, 2017	36,708
Consolidated Statements of Changes in Stockholders’ Equity
Issuance of ordinary shares	$ 230	73,989			74,219
Issuance of ordinary shares (in shares)	22,974
Equity transaction costs		(4,933)			(4,933)
Stock-based compensation expense		5,154			5,154
Shares issued in connection with the acquisition of Zavante Therapeutics, Inc.	$ 73	26,829			26,902
Shares issued in connection with the acquisition of Zavante Therapeutics, Inc. (in shares)	7,337
Net loss				(114,780)	(114,780)
Stockholders' equity, ending balance at Dec. 31, 2018	$ 670	461,911	27	(393,978)	68,630
Stockholders' equity, ending balance (in shares) at Dec. 31, 2018	67,019
Consolidated Statements of Changes in Stockholders’ Equity
Issuance of ordinary shares and warrants	$ 258	47,824			48,082
Issuance of ordinary shares and warrants (in shares)	25,838
Equity transaction costs		(2,794)			(2,794)
Stock-based compensation expense		9,748			9,748
Shares issued in connection with the vesting of restricted stock units	$ 7	(7)
Shares issued in connection with the vesting of restricted stock units (in shares)	659
Shares issued in connection with the employee stock purchase plan	$ 2	370			372
Shares issued in connection with the employee stock purchase plan (in shares)	214
Shares issued in connection with the acquisition of Zavante Therapeutics, Inc.	$ 8	(8)
Shares issued in connection with the acquisition of Zavante Therapeutics, Inc. (in shares)	815
Net loss				(82,764)	(82,764)
Stockholders' equity, ending balance at Dec. 31, 2019	$ 945	$ 517,044	$ 27	$ (476,742)	$ 41,274
Stockholders' equity, ending balance (in shares) at Dec. 31, 2019	94,545