INCOME TAXES (Deferred Tax Assets) (Details) - USD ($) $ in Thousands	Feb. 28, 2018	Feb. 28, 2017
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$ 10,343	$ 23,751
Depreciation, amortization and impairments	(11,325)	(21,959)
Research and development credits	14,404	12,307
Stock-based compensation	2,376	2,855
Other tax credits	2,015	3,650
Inventory reserve	292	903
Warranty reserve	429	670
Payroll and employee benefit accruals	1,941	3,012
Allowance for doubtful accounts	354	961
Other accrued liabilities	8,794	6,738
Other, net	3,710	1,203
Gross deferred tax assets	33,333	34,091
Valuation allowance	(1,752)	(6,587)
Net deferred tax assets	$ 31,581	$ 27,504