Income Taxes (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			6 Months Ended
	Feb. 28, 2013	Feb. 29, 2012	Nov. 30, 2011	Feb. 28, 2013	Feb. 29, 2012
Income Tax Disclosure [Abstract]
Effective Income Tax Rate, Continuing Operations	50.60%	35.00%		33.50%	(110.70%)
Effective tax rate from discontinued operations	34.80%	42.90%		35.10%	35.40%
Net Income tax payments (refunds)				$ (2.2)	$ 13.7
Statutory tax rate					35.00%
Gross unrecognized tax benefits	27.4	12.4		27.4	12.4
Possible unrecognized tax benefits reduction during the next twelve months	17.8			17.8
Statement [Line Items]
Tax benefit related to investment in subsidiary			102.1
CMCS [Member]
Statement [Line Items]
Tax loss related to investment in subsidiary			$ 291