Supporting Financial Information - Accounts Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Billed receivables	$ 23,261	$ 18,924
Contract assets	4,734	4,302
Total accounts receivable	27,995	23,226
Less: Allowance for doubtful accounts	0	0
Accounts receivable, net	$ 27,995	$ 23,226

Amounts due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer) for goods or services (including trade receivables) that have been delivered or sold in the normal course of business.

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Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.

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- Definition

A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible.

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- Definition

Amounts due for billed services rendered or to be rendered, actions taken or to be taken, or a promise to refrain from taking certain actions in accordance with the terms of a legally binding agreement between the Company and, at a minimum, one other party. An example would be amounts billed to customers under contracts or programs but not paid as of the balance sheet date.

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Amount, before allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time, classified as current.

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