Annual report pursuant to Section 13 and 15(d)

Business Segments and Customer Information - Narrative (Details)

v3.10.0.1
Business Segments and Customer Information - Narrative (Details)
$ in Thousands
3 Months Ended 12 Months Ended
Sep. 30, 2018
USD ($)
Dec. 31, 2018
USD ($)
segment
Dec. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
Segment Reporting Information [Line Items]        
Number of reportable operating segments | segment   3    
Gain on sale of contract $ 1,700 $ 1,700 $ 0 $ 0
Corporate        
Segment Reporting Information [Line Items]        
Gain resulting from the combined effect of the Anchorage Lawsuit and Maritime Administration settlements       1,400
Corporate | Heritage Litigation        
Segment Reporting Information [Line Items]        
Settlement amount       $ 3,300
Unspecified Customer One | IT Contract | Federal Services Group        
Segment Reporting Information [Line Items]        
Gain on sale of contract $ 1,700