Basis of Presentation of Unaudited Interim Condensed Consolidated Financial Statements and Significant Accounting Policies - ASC 606 Balance Sheet (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Sep. 30, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	$ 44,721	$ 49,819	[1]
Property, equipment and improvements, net	14,417	8,354	[1]
Deferred tax assets	5,343	6,600	[1]
Unearned revenue current		3,177
Other non-current liabilities	4,192	720	[1]
Retained earnings	$ 159,633	151,961	[1]
As Reported
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net		50,817
Property, equipment and improvements, net		6,270
Deferred tax assets		6,665
Unearned revenue current		2,579
Other non-current liabilities		510
Retained earnings		151,748
Impact of Adoption | ASU 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net		(998)
Property, equipment and improvements, net		2,084
Deferred tax assets		(65)
Unearned revenue current		598
Other non-current liabilities		210
Retained earnings		$ 213

[1] Prior period information has been restated for the adoption of ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606),” which we adopted on October 1, 2018.