Related Party Transactions - Tender Offer for Shares (Details) - $ / shares		12 Months Ended
Nov. 11, 2016	Sep. 30, 2018
Five Star \| ABP Acquisition LLC
Related Party Transaction [Line Items]
Lock-up period	10 years
Non-engagement period	10 years
Common stock \| Five Star \| ABP Acquisition LLC
Related Party Transaction [Line Items]
Shares purchased (in shares)	17,999,999
Price of share (in dollars per share)	$ 3.00
Common stock \| Five Star \| The Founders, ABP Trust and ABP Acquisition LLC
Related Party Transaction [Line Items]
Number of shares owned (in shares)	18,339,621	18,162,999
Ownership percentage	36.80%	36.40%
Up C Transaction
Related Party Transaction [Line Items]
Lock-up period		10 years

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- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

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Price of a single share of a number of saleable stocks of a company.

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