Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2012	Mar. 31, 2012
Accounts receivable, allowance for doubtful accounts	$ 565	$ 226
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued
Preferred stock, shares outstanding
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	48,401,084	48,185,731
Common stock, shares outstanding	41,709,141	41,814,191
Treasury stock, shares	6,691,943	6,371,540