Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data	Sep. 30, 2011	Mar. 31, 2011
Condensed Consolidated Balance Sheets [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 301	$ 346
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	47,740,710	47,441,879
Common stock, shares outstanding	41,506,731	42,557,221
Treasury stock, shares	6,233,979	4,884,658