Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data	Sep. 30, 2011	Mar. 31, 2011
Condensed Consolidated Balance Sheets [Abstract]
Accounts receivable, allowances	$ 248	$ 661
Intangible assets, accumulated amortization	$ 21,601	$ 20,069
Common stock, no par value
Common stock, stated value	$ 0.30	$ 0.30
Common stock, shares authorized	80,000,000	80,000,000
Common stock, shares issued	31,606,831	31,606,831
Common stock, shares outstanding	22,575,300	23,022,398
Treasury shares	9,031,531	8,584,433