CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY AND COMPREHENSIVE INCOME (LOSS) (Unaudited) (Parenthetical) (USD $)	6 Months Ended	12 Months Ended
	Sep. 30, 2011	Mar. 31, 2011
CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY AND COMPREHENSIVE INCOME (Unaudited) [Abstract]
Proceeds from exercise of stock options (in shares)	68,700	447,250
Proceeds from exercise of stock options, tax benfits	$ 462,974	$ 1,923,628
Common stock repurchases (in shares)	1,153,700	1,298,057
Issuance of restricted common stock under stock option plan (in shares)	10,000	54,951