Quarterly report pursuant to Section 13 or 15(d)

Business Segments and Customer Information, Major Customers (Details)

v2.4.1.9
Business Segments and Customer Information, Major Customers (Details) (USD $)
In Thousands, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Revenue, Major Customer [Line Items]    
Revenue $ 120,791us-gaap_Revenues $ 119,409us-gaap_Revenues
Revenue by customer (in hundredths) 100.00%us-gaap_ConcentrationRiskPercentage1 100.00%us-gaap_ConcentrationRiskPercentage1
U.S. Navy [Member]    
Revenue, Major Customer [Line Items]    
Revenue 21,397us-gaap_Revenues
/ us-gaap_MajorCustomersAxis
= vsec_USNavyMember
24,614us-gaap_Revenues
/ us-gaap_MajorCustomersAxis
= vsec_USNavyMember
Revenue by customer (in hundredths) 17.70%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_MajorCustomersAxis
= vsec_USNavyMember
20.60%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_MajorCustomersAxis
= vsec_USNavyMember
U.S. Army/Army Reserve [Member]    
Revenue, Major Customer [Line Items]    
Revenue 19,171us-gaap_Revenues
/ us-gaap_MajorCustomersAxis
= vsec_USArmyArmyReserveMember
33,698us-gaap_Revenues
/ us-gaap_MajorCustomersAxis
= vsec_USArmyArmyReserveMember
Revenue by customer (in hundredths) 15.90%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_MajorCustomersAxis
= vsec_USArmyArmyReserveMember
28.20%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_MajorCustomersAxis
= vsec_USArmyArmyReserveMember
U.S. Air Force [Member]    
Revenue, Major Customer [Line Items]    
Revenue 790us-gaap_Revenues
/ us-gaap_MajorCustomersAxis
= vsec_USAirForceMember
796us-gaap_Revenues
/ us-gaap_MajorCustomersAxis
= vsec_USAirForceMember
Revenue by customer (in hundredths) 0.70%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_MajorCustomersAxis
= vsec_USAirForceMember
0.70%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_MajorCustomersAxis
= vsec_USAirForceMember
Total DoD [Member]    
Revenue, Major Customer [Line Items]    
Revenue 41,358us-gaap_Revenues
/ us-gaap_MajorCustomersAxis
= vsec_TotalDepartmentOfDefenseMember
59,108us-gaap_Revenues
/ us-gaap_MajorCustomersAxis
= vsec_TotalDepartmentOfDefenseMember
Revenue by customer (in hundredths) 34.30%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_MajorCustomersAxis
= vsec_TotalDepartmentOfDefenseMember
49.50%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_MajorCustomersAxis
= vsec_TotalDepartmentOfDefenseMember
U.S. Postal Service [Member]    
Revenue, Major Customer [Line Items]    
Revenue 44,180us-gaap_Revenues
/ us-gaap_MajorCustomersAxis
= vsec_UsPostalServiceMember
39,329us-gaap_Revenues
/ us-gaap_MajorCustomersAxis
= vsec_UsPostalServiceMember
Revenue by customer (in hundredths) 36.60%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_MajorCustomersAxis
= vsec_UsPostalServiceMember
32.90%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_MajorCustomersAxis
= vsec_UsPostalServiceMember
Department of Energy [Member]    
Revenue, Major Customer [Line Items]    
Revenue 4,444us-gaap_Revenues
/ us-gaap_MajorCustomersAxis
= vsec_DepartmentOfEnergyMember
4,626us-gaap_Revenues
/ us-gaap_MajorCustomersAxis
= vsec_DepartmentOfEnergyMember
Revenue by customer (in hundredths) 3.70%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_MajorCustomersAxis
= vsec_DepartmentOfEnergyMember
3.90%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_MajorCustomersAxis
= vsec_DepartmentOfEnergyMember
Department of Treasury [Member]    
Revenue, Major Customer [Line Items]    
Revenue 415us-gaap_Revenues
/ us-gaap_MajorCustomersAxis
= vsec_DepartmentOfTreasuryMember
8,358us-gaap_Revenues
/ us-gaap_MajorCustomersAxis
= vsec_DepartmentOfTreasuryMember
Revenue by customer (in hundredths) 0.30%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_MajorCustomersAxis
= vsec_DepartmentOfTreasuryMember
7.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_MajorCustomersAxis
= vsec_DepartmentOfTreasuryMember
Other Government [Member]    
Revenue, Major Customer [Line Items]    
Revenue 6,423us-gaap_Revenues
/ us-gaap_MajorCustomersAxis
= us-gaap_GovernmentMember
7,179us-gaap_Revenues
/ us-gaap_MajorCustomersAxis
= us-gaap_GovernmentMember
Revenue by customer (in hundredths) 5.30%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_MajorCustomersAxis
= us-gaap_GovernmentMember
6.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_MajorCustomersAxis
= us-gaap_GovernmentMember
Total Federal Civilian Agencies [Member]    
Revenue, Major Customer [Line Items]    
Revenue 55,462us-gaap_Revenues
/ us-gaap_MajorCustomersAxis
= vsec_TotalFederalCivilAgenciesMember
59,492us-gaap_Revenues
/ us-gaap_MajorCustomersAxis
= vsec_TotalFederalCivilAgenciesMember
Revenue by customer (in hundredths) 45.90%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_MajorCustomersAxis
= vsec_TotalFederalCivilAgenciesMember
49.80%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_MajorCustomersAxis
= vsec_TotalFederalCivilAgenciesMember
Commercial [Member]    
Revenue, Major Customer [Line Items]    
Revenue $ 23,971us-gaap_Revenues
/ us-gaap_MajorCustomersAxis
= vsec_CommercialMember
$ 809us-gaap_Revenues
/ us-gaap_MajorCustomersAxis
= vsec_CommercialMember
Revenue by customer (in hundredths) 19.80%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_MajorCustomersAxis
= vsec_CommercialMember
0.70%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_MajorCustomersAxis
= vsec_CommercialMember