Revenue from Contracts with Clients (Details)	3 Months Ended		9 Months Ended
	Jun. 30, 2020 Rate	Jun. 30, 2019 Rate	Jun. 30, 2020 Rate	Jun. 30, 2019 Rate
Revenues from Contracts With Clients [Abstract]
Revenues from contracts with clients as a % of total revenues	1.40%	1.50%	0.90%	1.60%
Revenues from contracts with clients as a % of operating revenues	35.80%	41.70%	37.60%	41.60%