Employee Benefit And Cash Incentive Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Aug. 31, 2015	Aug. 31, 2014	Aug. 31, 2013
Defined Contribution Plans [Line Items]
Employer contributions	$ 1.6	$ 1.3	$ 1.9
Incentive bonus expense	$ 12.4	$ 9.5	$ 8.2
Maximum [Member]
Defined Contribution Plans [Line Items]
Employer contributions, percentage	6.00%