Commitments and Contingencies (Letters of Credit) (Details) $ in Millions	Sep. 30, 2017 USD ($)
Standby Letters of Credit
Line of Credit Facility [Line Items]
Letters of credit	$ 0.4

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