Receivables

The following table presents the components of receivables appearing in the accompanying Consolidated Balance Sheets at March 31, 2017 and September 30, 2016, as well as certain other related information (in thousands):

	March 31, 2017		September 30, 2016
Components of receivables:
Amounts billed	$	927,500	$	1,110,042
Unbilled receivables and other		1,090,918		937,552
Retentions receivable		39,587		68,069
Total receivables, net	$	2,058,005	$	2,115,663
Other information about receivables:
Amounts due from the United States federal government, included above, net of advanced billings	$	212,969	$	235,203
Claims receivable	$	26,169	$	26,061

“Amounts billed” consist of amounts invoiced to clients in accordance with the terms of our client contracts and are shown net of an allowance for doubtful accounts. We anticipate that substantially all of such billed amounts will be collected over the next twelve months.

“Unbilled receivables and other” and “Retentions receivable” represent reimbursable costs and amounts earned and reimbursable under contracts in progress as of the respective balance sheet dates. Such amounts become billable according to the contract terms, which usually provide that such amounts become billable upon the passage of time, achievement of certain milestones, or completion of the project. We anticipate that substantially all of such unbilled amounts will be billed and collected over the next twelve months.

“Claims receivable” are included in receivables in the accompanying Consolidated Balance Sheets and represent certain costs incurred on contracts to the extent it is probable that such claims will result in additional contract revenue and the amount of such additional revenue can be reliably estimated.