Commitments and Contingencies - Operating Leases (Details) $ in Millions	9 Months Ended
	Jun. 30, 2017 USD ($) ft²
Property Subject to or Available for Operating Lease [Line Items]
Lease renewal term	5 years
Non-cancelable obligations, operating lease | $	$ 2.4
Lease Arrangement Expiring July 2017
Property Subject to or Available for Operating Lease [Line Items]
Area leased (in sq ft)	85,000
Lease Arrangement, March 2019 To September 2023
Property Subject to or Available for Operating Lease [Line Items]
Area leased (in sq ft)	13,000