Leases (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Aug. 31, 2020	Aug. 31, 2019	Aug. 31, 2018
Operating Leased Assets [Line Items]
Right-of-use operating lease assets obtained in exchange for operating lease liabilities	$ 1.5
Total rent expense	1.5	$ 1.5	$ 1.6
Sublease revenue	$ 3.9	$ 3.9	$ 3.5
Minimum [Member]
Operating Leased Assets [Line Items]
Remaining operating lease term	1 year
Maximum [Member]
Operating Leased Assets [Line Items]
Remaining operating lease term	5 years
Corporate Campus [Member]
Operating Leased Assets [Line Items]
Cost basis	$ 36.0
Carrying value	$ 5.9