Revenues and Receivables

12 Months Ended

Dec. 31, 2011

Revenues and Receivables [Abstract]

Revenues and Receivables

Revenues and Receivables

We deliver a broad array of information technology and technical services solutions under contracts with the U.S. government, state and local governments and commercial customers. Revenues from the U.S. government under prime contracts and subcontracts, as compared to total contract revenues, were approximately 99.2%, 98.7% and 98.3% for the years ended December 31, 2011, 2010 and 2009, respectively. The components of contract receivables are as follows (in thousands):

	December 31,
	2011			2010
Billed receivables	$	422,954		$	411,018
Unbilled receivables:
Amounts billable	101,997			103,752
Revenues recorded in excess of funding	19,982			16,508
Retainage	5,264			6,433
Allowance for doubtful accounts	(9,729		)	(8,946		)
Total receivables, net	$	540,468		$	528,765

Amounts billable consist principally of amounts to be billed within the next month. Revenues recorded in excess of funding are billable upon receipt of contractual amendments or other modifications. Revenues recorded in excess of milestone billings on fixed price contracts consist of amounts not expected to be billed within the next month. The retainage is billable upon completion of the contract performance and approval of final indirect expense rates by the government. Accounts receivable at December 31, 2011 are expected to be substantially collected in 2012 except for approximately $2.1 million, of which 93.6% is related to receivables from sales to the U.S. government. The remainder is related to receivables from contracts in which we acted as a subcontractor to other contractors.

The Company does not believe it has significant exposure to credit risk as accounts receivable and the related unbilled amounts are primarily due from the U.S. government. The allowance for doubtful accounts represents the Company's estimate for exposure to compliance, contractual issues and bad debts related to prime contractors.