CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Revenue:
Total revenue	$ 6,723	$ 5,859	$ 20,853	$ 18,595
Cost of revenue	(4,186)	(2,325)	(12,803)	(7,943)
Gross profit	2,537	3,534	8,050	10,652
Operating expenses:
Sales and marketing	(2,233)	(1,910)	(6,359)	(5,461)
Research and development, net of government grants	(11,788)	(11,929)	(37,356)	(37,944)
General and administrative expense:
Compensation expense in respect of share options and management equity incentives	(1,073)	(986)	(3,576)	(3,458)
Other general and administrative expenses	(6,471)	(5,804)	(19,388)	(15,851)
Total general and administrative expense	(7,544)	(6,790)	(22,964)	(19,309)
Total operating expense	(21,565)	(20,629)	(66,679)	(62,714)
Operating loss	(19,028)	(17,095)	(58,629)	(52,062)
Other income (expense):
Interest expense, net	(5,679)	(3,249)	(14,614)	(11,656)
Other, net	(1,536)	33	(5,516)	1,478
Other expense, net	(7,215)	(3,216)	(20,130)	(10,178)
Loss before income taxes	(26,243)	(20,311)	(78,759)	(62,240)
Provision for income taxes	(11)		(33)
Net loss	(26,254)	(20,311)	(78,792)	(62,240)
Other comprehensive income (loss):
Change in fair value of effective portion of foreign currency cash flow hedges	41	(64)	(320)	409
Change in unrealized gain on short-term investments	169	(7)	416	25
Foreign currency gain (loss)	(176)	(168)	554	1,144
Provision for pension benefit obligation	35	45	107	132
Other comprehensive income (loss), net	69	(194)	757	1,710
Comprehensive loss	(26,185)	(20,505)	(78,035)	(60,530)
Net loss available to ordinary shareholders - basic and diluted	$ (26,254)	$ (20,311)	$ (78,792)	$ (62,240)
Loss per share - basic and diluted	$ (0.46)	$ (0.47)	$ (1.53)	$ (1.58)
Weighted-average shares outstanding - basic and diluted	56,619,356	43,353,506	51,512,352	39,274,570
Product Sales [Member]
Revenue:
Total revenue	$ 6,723	$ 5,653	$ 20,834	$ 17,789
Other Revenues [Member]
Revenue:
Total revenue		$ 206	$ 19	$ 806