Unaudited Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2019	Mar. 31, 2019
Current assets:
Cash and cash equivalents	$ 73,952	$ 77,483
Accounts receivable, net	10,736	7,855
Inventory	11,924	12,119
Note receivable, current portion		2,888
Prepaid expenses and other current assets	4,102	3,053
Total current assets	100,714	103,398
Property, plant and equipment, net	8,747	8,972
Intangibles, net	2,805	2,890
Goodwill	1,719	1,719
Restricted cash	715	715
Right-of-use asset	3,733	0
Deferred tax assets	1,411	1,357
Other assets	306	279
Total assets	120,150	119,330
Current liabilities:
Accounts payable and accrued expenses	15,819	15,885
Lease liability, current portion	416	0
Derivative liabilities	1,702	4,942
Deferred revenue, current portion	10,806	7,557
Total current liabilities	28,743	28,384
Deferred revenue, long term portion	7,883	7,962
Lease liability, long term portion	3,357	0
Deferred tax liabilities	1,703	1,698
Other liabilities	51	93
Total liabilities	41,737	38,137
Commitments and contingencies (Note 15)
Stockholders' equity:
Common stock	218	216
Additional paid-in capital	1,045,244	1,044,622
Treasury stock	(2,384)	(2,101)
Accumulated other comprehensive (loss) income	413	(5)
Accumulated deficit	(965,078)	(961,539)
Total stockholders' equity	78,413	81,193
Total liabilities and stockholders' equity	$ 120,150	$ 119,330