Accounts Receivable and Unbilled Accounts Receivable (Schedule of Major Customers, by Percentage of Accounts Receivable) (Details) (Trade accounts receivable [Member], Customer Concentration Risk [Member])	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Transportation Security Administration ("TSA") [Member]
Concentration Risk [Line Items]
As a % of Receivables	12.00%	12.00%
Department of Homeland Security ("DHS") [Member]
Concentration Risk [Line Items]
As a % of Receivables	13.00%	19.00%
Bureau of Alcohol Tabacco and Firearms ("ATF") [Member]
Concentration Risk [Line Items]
As a % of Receivables		10.00%