Debt and Other Obligations Lease/Leaseback Obligations (Details) $ in Millions	Jun. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)
Sale Leaseback Transaction [Line Items]
Leasing transaction, number of units		24
CT and QTE outstanding leaseback obligation	$ 263	$ 301

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_SaleLeasebackTransactionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration