Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 65,775	$ 76,494
Restricted cash	146	87
Accounts receivable, net	5,023	4,754
Inventory	6,686	5,450
Prepaid expenses and other	2,800	2,242
Total current assets	80,430	89,027
Restricted cash, non-current	246	362
Property and equipment, net	3,907	2,964
Intangible assets, net	321	331
Other assets	12	60
Total assets	84,916	92,744
Current liabilities:
Accounts payable	4,152	2,310
Accrued liabilities	4,670	6,936
Deferred income	2,428	1,540
Current portion of loans payable	176	170
Taxes payable	1	177
Total current liabilities	11,427	11,133
Long-term portion of loans payable	475	563
Other liabilities		296
Total liabilities	11,902	11,992
Shareholders’ equity:
Ordinary shares, £0.006705 nominal value; 40,103,528 and 25,189,285 shares authorized at June 30, 2014 and December 31, 2013, respectively, and 17,573,789 and 17,255,267 shares issued and outstanding at June 30, 2014 and December 31, 2013, respectively	192	188
Additional paid-in capital	185,314	183,967
Accumulated deficit	(109,042)	(99,655)
Accumulated other comprehensive loss	(3,450)	(3,748)
Total shareholders’ equity	73,014	80,752
Total liabilities and shareholders’ equity	$ 84,916	$ 92,744