Revenue from Contracts with Customers Contract Balances (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Sep. 30, 2018
Contract with Customer, Asset and Liability [Abstract]
Receivables, which are included in “Accounts receivable, net”		$ 250,960	$ 270,181
Deferred revenue	$ 108,118	$ 108,167	$ 108,118
Contract With Customer, Liability [Roll Forward]
Deferred revenues, beginning balance	108,118
Revenue recognized that was included in the deferred revenues balance at the beginning of the period	(53,339)
Increases due to billings, excluding amounts recognized as revenue during the period	53,388
Deferred revenues, ending balance	$ 108,167
Minimum
Disaggregation of Revenue [Line Items]
Payment term	30 days
Maximum
Disaggregation of Revenue [Line Items]
Payment term	60 days