Concentration of Risk and Segment Data - Segment Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	May 31, 2018	May 31, 2017	May 31, 2018	May 31, 2017
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenue	$ 5,436,952	$ 4,489,557	$ 16,323,585	$ 14,040,092
EMS | Operating Segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenue	3,161,626	2,819,711	8,894,174	8,205,812
DMS | Operating Segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenue	$ 2,275,326	$ 1,669,846	$ 7,429,411	$ 5,834,280