Commitments and Contingencies - Contingencies (Details) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
Jun. 30, 2017	Sep. 30, 2016
Loss Contingency [Abstract]
Common stock, shares issued	83,216,169	82,220,270
Employee Stock Purchase Plan, Rescission Rights \| Employee Stock
Loss Contingency [Abstract]
Common stock, shares issued	36,531
Share price (in dollars per share)	$ 8.02
Estimate of aggregate payments	$ 0.3

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_CommonStockSharesIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant