Accounts Receivable and Unbilled Accounts Receivables (Details 3)	Jun. 30, 2012	Dec. 31, 2011
Transportation Security Administration [Member]
As a % of Receivables	10.00%	11.00%
Department Of Homeland Security [Member]
As a % of Receivables	23.00%	20.00%
Bureau Of Alcohol, Tabacco Firearms [Member]
As a % of Receivables	12.00%	0.00%