INCOME TAXES (Deferred Tax Assets) (Details) - USD ($) $ in Thousands	Feb. 28, 2019	Feb. 28, 2018
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$ 19,269	$ 22,013
Depreciation, amortization and impairments	(11,945)	(11,112)
Research and development credits	19,189	17,432
Stock-based compensation	2,783	2,376
Other tax credits	1,018	2,015
Inventory reserve	624	292
Warranty reserve	313	429
Payroll and employee benefit accruals	2,220	1,941
Allowance for doubtful accounts	454	354
Other accrued liabilities	6,208	8,975
Convertible debt	(10,822)	(194)
Other, net	3,281	3,904
Gross deferred tax assets	32,592	48,425
Valuation allowance	(10,929)	(16,844)
Net deferred tax assets	21,663	31,581
Reported as:
Deferred tax assets	22,626	31,581
Deferred tax liabilities	(963)
Net deferred tax assets	$ 21,663	$ 31,581