Loss Per Share (Detail) - Schedule of Calculation of Numerator and Denominator in Earnings Per Share (USD $) In Millions, except Per Share data	3 Months Ended
	Aug. 31, 2011	Aug. 31, 2010
Loss from continuing operations attributable to Class A and Common Shares (in Dollars)	$ (25.1)	$ (33.9)
Loss from discontinued operations attributable to Class A and Common Shares, net of tax (in Dollars)	(2.0)	(1.3)
Net loss attributable to Class A and Common Shares (in Dollars)	$ (27.1)	$ (35.2)
Weighted average Shares of Class A Stock and Common Stock outstanding for basic loss per share (in millions) (in Shares)	31.0	36.1
Basic:
Loss from continuing operations	$ (0.81)	$ (0.94)
Loss from discontinued operations, net of tax	$ (0.06)	$ (0.04)
Net loss	$ (0.87)	$ (0.98)
Diluted:
Loss from continuing operations	$ (0.81)	$ (0.94)
Loss from discontinued operations, net of tax	$ (0.06)	$ (0.04)
Net loss	$ (0.87)	$ (0.98)