Supporting Financial Information - Accounts Receivable (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Sep. 30, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total accounts receivable	$ 11,911	$ 6,637
Less: Allowance for doubtful accounts	0	0
Accounts receivable, net	11,911	6,637
Billed Receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total accounts receivable	11,862	5,265
Unbilled Receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total accounts receivable	$ 49	$ 1,372