Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended
	Feb. 28, 2015 Segment	Feb. 28, 2014	Jan. 20, 2014
Summary Of Significant Accounting Policies [Line Items]
Long -term debt	$ 233,000	$ 281,000
Working capital	13,100,000
Liquid assets	2,600,000
Shipping costs	200,000	100,000
Research and development costs	100,000	300,000
Unrealized gains and losses on trading investments	(2,800,000)	100,000
Inventories written-off during the period	300,000	1,800,000
Provision for inventory reserve	519,000	658,000
Depreciation expense	253,000	268,000
Total unrecognized compensation costs related to stock options and shares of restricted stock granted	10,000
Unrecognized compensation cost is expected to be recognized over a period	1 year
Authorized stock repurchase	2,632,500
Additional authorized stock repurchase			1,500,000
Number of shares repurchased	1,058,459	572,597
Average price of repurchase shares	$ 3.35	$ 3.78
Remaining repurchase of shares authorized	574,050
Unrecognized tax benefits	0	0
Unrecognized tax benefits, interest and penalties accrued	0	0
Stock options, debentures, and other liabilities convertible into shares excluded from diluted earnings per (loss) share calculation	73,000	38,000
Number of reportable segments	1
Raw Material Parts and Demo Equipment
Summary Of Significant Accounting Policies [Line Items]
Provision for inventory reserve	$ 100,000
Non U S | Sales Revenue, Goods, Net | Customer Concentration Risk
Summary Of Significant Accounting Policies [Line Items]
Consolidated net sales percentage	15.00%	10.00%
Building | Minimum
Summary Of Significant Accounting Policies [Line Items]
Useful life	10 years
Building | Maximum
Summary Of Significant Accounting Policies [Line Items]
Useful life	25 years
Machinery and Equipment | Minimum
Summary Of Significant Accounting Policies [Line Items]
Useful life	5 years
Machinery and Equipment | Maximum
Summary Of Significant Accounting Policies [Line Items]
Useful life	10 years