Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2011	Mar. 31, 2011
Shareholders' equity:
Common stock, par value
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	36,874,435	36,577,605
Common stock, shares outstanding	36,874,435	36,577,605