Share-Based Compensation (Details 2) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	3 Months Ended
	Nov. 30, 2011
Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized shared-based compensation cost	$ 28.7
Restricted stock units and performance share awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized shared-based compensation cost	$ 104.9
Awards other than options granted	67
Weighted average grant date fair value other than options	$ 43.18