Summary of Significant Accounting Policies (Government Contracts) (Details) - USD ($) $ in Thousands			12 Months Ended
	Aug. 15, 2012	May. 13, 2010	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Significant Accounting Policies [Line Items]
Contracts revenue			$ 628,451	$ 603,975	$ 572,266
Government Contracts [Member] | T-3 Contract [Member]
Significant Accounting Policies [Line Items]
Number of administrative services option periods		5 years
Government Contracts [Member] | MFLC Contract [Member]
Significant Accounting Policies [Line Items]
Effective date of contract			August 15, 2012
Administrative services option period	5 years