12. Subsequent Events (Detail) (USD $)	1 Months Ended		3 Months Ended		6 Months Ended	9 Months Ended
	Feb. 28, 2012	Dec. 31, 2011	Oct. 30, 2011	Oct. 31, 2010	Oct. 30, 2011	Oct. 30, 2011	Oct. 31, 2010
Dividends Payable, Date Declared, Day, Month and Year		Dec. 06, 2011
Common Stock, Dividends, Per Share, Declared (in Dollars per share)			$ 0.10	$ 0.10	$ 0.10	$ 0.30	$ 0.30
Dividends Payable, Date to be Paid, Day, Month and Year	Feb. 24, 2012
Dividends Payable, Date of Record, Day, Month and Year	Feb. 10, 2012