Revenue and Accounts Receivable (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Accounts Receivable [Line Items]
Concentration risk, percentage (in hundredths)									100.00%		100.00%		100.00%
Components of Accounts Receivable [Abstract]
Billed accounts receivable	$ 21,476				$ 26,299				$ 21,476		$ 26,299
Unbilled receivables	12,722				11,022				12,722		11,022
Allowance for doubtful accounts	(319)				(375)				(319)		(375)		(358)
Accounts Receivable, Net, Total	33,879				36,946				33,879		36,946
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance Beginning of Year				375				358	375		358		363
Bad Debt Expenses									(53)	[1]	17	[1]	(3)	[1]
Deductions									(3)	[2]	0	[2]	(2)	[2]
Balance End of Year	319				375				319		375		358
Revenue by Customer Sector [Abstract]
Revenue	48,413	66,916	56,338	54,429	47,784	52,982	41,145	47,977	226,096		189,888		225,797
Federal [Member]
Revenue by Customer Sector [Abstract]
Revenue									224,010		188,162		220,017
Federal [Member] | Revenue from Contracts and Subcontracts [Member]
Accounts Receivable [Line Items]
Concentration risk, percentage (in hundredths)									99.10%		99.10%		97.40%
Federal [Member] | Accounts Receivable [Member]
Accounts Receivable [Line Items]
Concentration risk, percentage (in hundredths)									97.00%
Commercial [Member]
Accounts Receivable [Line Items]
Concentration risk, percentage (in hundredths)									0.90%		0.90%		2.60%
Revenue by Customer Sector [Abstract]
Revenue									$ 2,086		$ 1,726		$ 5,780

[1] Accounts receivable reserves and reversal of allowance for subsequent collections, net

[2] Accounts receivable written-off and subsequent recoveries, net