Annual report pursuant to Section 13 and 15(d)

Business Segments and Customer Information - Narrative (Details)

v3.20.1
Business Segments and Customer Information - Narrative (Details)
$ in Thousands
3 Months Ended 12 Months Ended
Sep. 30, 2018
USD ($)
Dec. 31, 2019
USD ($)
segment
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Segment Reporting Information [Line Items]        
Number of reportable operating segments | segment   3    
Gain on sale of contract $ 1,700 $ 0 $ 1,700 $ 0
Federal Services Group        
Segment Reporting Information [Line Items]        
Increase (decrease) in depreciation and amortization expense     (8,100) (9,100)
Aviation        
Segment Reporting Information [Line Items]        
Increase (decrease) in depreciation and amortization expense     3,700 4,100
Supply Chain Management        
Segment Reporting Information [Line Items]        
Increase (decrease) in depreciation and amortization expense     $ 4,400 $ 5,000
Unspecified Customer One | IT Contract | Federal Services Group        
Segment Reporting Information [Line Items]        
Gain on sale of contract $ 1,700