Income Taxes (Schedule of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Mar. 31, 2015
Income Tax Disclosure [Abstract]
Inventory, accruals and reserves	$ 3,686	$ 5,297
Other	187	159
Deferred revenue	73	91
Valuation allowance	(3,946)	(5,547)
Total net current deferred tax assets and liabilities	0	0
Federal and state operating loss carryforwards	19,727	13,154
Tax credit carryforwards	1,475	1,475
Non-qualified stock options	3,125	2,914
Deferred revenue	(31)	7
Fixed assets	(1,493)	(1,698)
Intangible assets	(1,297)	(1,687)
Valuation allowance	(21,506)	(14,165)
Total net long-term deferred tax assets and liabilities	0	0
Total net deferred tax assets	$ 0	$ 0