Accounts Receivable and Unbilled Accounts Receivables (Details 2)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Transportation Security Administration [Member]
As a % of Revenues	18.00%	23.00%	18.00%	24.00%
Department Of Homeland Security [Member]
As a % of Revenues	15.00%	28.00%	17.00%	28.00%