Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Assets
Cash and cash equivalents	$ 187,291	$ 192,844
Accounts receivable, net	13,778	9,158
Other receivable	9,115	4,500
Inventory, net	9,957	7,767
Prepaid expenses and other assets	3,199	2,511
Total current assets	223,340	216,780
Restricted cash, non-current	100	100
Other receivable, non-current		4,500
Property and equipment, net	6,658	7,144
Operating lease right-of-use assets	6,892
Goodwill	2,483	2,483
Net Carrying Amount, Finite-Lived Intangible Assets	50	61
Deferred tax asset	2,508	1,052
Total assets	242,031	232,120
Liabilities and shareholders' equity
Accounts payable	2,519	2,801
Accrued liabilities	9,227	10,891
Current portion of operating lease liability	480
Settlement liability	4,289	4,106
Deferred income	214	125
Current portion of loans payable		85
Total current liabilities	16,729	18,008
Long-term portion of operating lease liability	7,489
Long-term portion of loans payable	30	106
Total liabilities	24,248	18,114
Commitments and contingencies (Note 12)
Shareholders' equity:
Ordinary shares, £0.006705 nominal value; 38,978,604 shares authorized at June 30, 2019 and December 31, 2018, and 26,807,101 and 26,439,334 shares issued and outstanding at June 30, 2019 and December 31, 2018, respectively	280	276
Additional paid-in capital	307,882	303,015
Accumulated deficit	(81,668)	(80,762)
Accumulated other comprehensive loss	(8,711)	(8,523)
Total shareholders' equity	217,783	214,006
Total liabilities and shareholders' equity	$ 242,031	$ 232,120