CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2011	Mar. 31, 2011
Current assets:
Trade receivables, less allowance for doubtful accounts	$ 575	$ 754
Shareholders' equity:
Preferred stock, par value (in dollars per share)	$ 0.025	$ 0.025
Preferred stock, shares authorized (in shares)	16,000	16,000
Common stock, par value (in dollars per shares)	$ 0.625	$ 0.625
Common stock, shares authorized (in shares)	80,000	80,000
Common stock, shares issued (in shares)	47,310	47,105
Treasury stock at cost: shares (in shares)	589	559