Subsequent Events - Additional Information (Details) (USD $)	3 Months Ended		9 Months Ended		0 Months Ended
	Feb. 28, 2014	Feb. 28, 2013	Feb. 28, 2014	Feb. 28, 2013	Mar. 06, 2014 Subsequent Event
Subsequent Event [Line Items]
Dividends payable, date declared					Mar. 05, 2014
Cash dividend declared per share (in dollars per share)	$ 0.20	$ 0	$ 0.60	$ 1.60	$ 0.20
Dividends payable, date to be paid					Apr. 10, 2014
Dividends payable, date of record					Mar. 20, 2014