Earnings (Loss) Per Share (Detail) - Summary of reconciliation of the numerators and denominators for the Basic and Diluted earnings (loss) per share (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Aug. 31, 2012		Aug. 31, 2011
Earnings (loss) from continuing operations attributable to Class A and Common Shares (in Dollars)	$ (31.9)		$ (25.0)
Earnings (loss) from discontinued operations attributable to Class A and Common Shares, net of tax (in Dollars)	(0.1)		(2.0)
Net income (loss) attributable to Class A and Common Shares (in Dollars)	$ (32.0)		$ (27.0)
Weighted average Shares of Class A Stock and Common Stock outstanding for basic earnings (loss) per share (in millions) (in Shares)	31.5		31.0
Dilutive effect of Class A Stock and Common Stock potentially issuable pursuant to stock-based compensation plans (in millions) (in Shares)		[1]		[1]
Adjusted weighted average Shares of Class A Stock and Common Stock outstanding for diluted earnings (loss) per share (in millions) (in Shares)		[1]		[1]
Basic earnings (loss) per share:
Earnings (loss) from continuing operations	$ (1.02)		$ (0.81)
Earnings (loss) from discontinued operations, net of tax	$ 0.00		$ (0.06)
Net income (loss)	$ (1.02)		$ (0.87)
Diluted earnings (loss) per share:
Earnings (loss) from continuing operations	$ (1.02)		$ (0.81)
Earnings (loss) from discontinued operations, net of tax	$ 0.00		$ (0.06)
Net income (loss)	$ (1.02)		$ (0.87)

[1] In the three months ended August 31, 2012 and 2011, the Company experienced a loss from continuing operations and therefore did not report any dilutive share impact.