Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Assets
Cash and cash equivalents	$ 189,518	$ 192,844
Accounts receivable, net	10,153	9,158
Other receivable	4,562	4,500
Inventory, net	9,944	7,767
Prepaid expenses and other assets	4,038	2,511
Total current assets	218,215	216,780
Restricted cash, non-current	100	100
Other receivable	4,500	4,500
Property and equipment, net	7,066	7,144
Operating lease right-of-use assets	7,223
Goodwill	2,483	2,483
Net Carrying Amount, Finite-Lived Intangible Assets	56	61
Deferred tax asset	1,667	1,052
Total assets	241,310	232,120
Liabilities and shareholders’ equity
Accounts payable	3,115	2,801
Accrued liabilities	9,377	10,891
Current portion of operating lease liability	484
Settlement liability	4,130	4,106
Deferred income	213	125
Current portion of loans payable		85
Total current liabilities	17,319	18,008
Long-term portion of operating lease liability	7,782
Long-term portion of loans payable	30	106
Total liabilities	25,131	18,114
Commitments and contingencies (Note 12)
Shareholders' equity:
Ordinary shares, £0.006705 nominal value; 38,978,604 shares authorized at March 31, 2019 and December 31, 2018, and 26,623,057 and 26,439,334 shares issued and outstanding at March 31, 2019 and December 31, 2018, respectively	278	276
Additional paid-in capital	305,515	303,015
Accumulated deficit	(82,258)	(80,762)
Accumulated other comprehensive loss	(7,356)	(8,523)
Total shareholders’ equity	216,179	214,006
Total liabilities and shareholders’ equity	$ 241,310	$ 232,120