Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	6 Months Ended	12 Months Ended
	Sep. 30, 2012	Mar. 31, 2012
Condensed Consolidated Balance Sheets
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	90,000,000	90,000,000
Common stock, shares outstanding	35,969,202	35,755,317
Treasury stock, shares	1,291,741	1,294,741
Treasury stock, shares, acquired	526,895	526,895