Energy Services Accounts Receivable Securitization Facility - Trade Receivables Transferred and Sold (Details) - ESFC - USD ($) $ in Millions	9 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Sep. 30, 2018
Accounts, Notes, Loans and Financing Receivable
Trade receivables transferred to ESFC during the period	$ 1,168.4	$ 1,051.7
ESFC trade receivables sold to the bank during the period	173.0	176.0
ESFC trade receivables - end of period	74.2	58.3	$ 65.0
Outstanding balance of trade receivables sold	$ 55.0	$ 0.0	$ 2.0