Concentration of Risk and Segment Data (Segment Assets) (Details 4) - USD ($) $ in Thousands	May 31, 2017	Aug. 31, 2016
Segment Reporting Asset Reconciling Item [Line Items]
Assets	$ 10,329,649	$ 10,322,677
EMS [Member]
Segment Reporting Asset Reconciling Item [Line Items]
Assets	2,802,613	2,615,237
DMS [Member]
Segment Reporting Asset Reconciling Item [Line Items]
Assets	5,030,763	5,012,798
Other non-allocated assets
Segment Reporting Asset Reconciling Item [Line Items]
Assets	$ 2,496,273	$ 2,694,642