Note 8 - Stock-Based Compensation Plans (Detail) - Recognized Stock-Based Compensation (Exclusive of Deferred Tax Benefits) For Awards Granted Under the Company's Stock Option Plans: (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011
Stock-based compensation expense before income tax benefits	$ 263	$ 140	$ 788	$ 470
Cost of Sales [Member]
Stock-based compensation expense before income tax benefits	16	8	43	34
Selling, General and Administrative Expenses [Member]
Stock-based compensation expense before income tax benefits	$ 247	$ 132	$ 745	$ 436