Quarterly report pursuant to Section 13 or 15(d)

Contracts in Progress - Additional Information (Details)

v3.19.3
Contracts in Progress - Additional Information (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2019
Sep. 30, 2019
Dec. 31, 2018
Property, Plant and Equipment [Line Items]      
Subcontract Payable Retainage $ 11.8 $ 11.8 $ 13.0
Mid-Atlantic project      
Property, Plant and Equipment [Line Items]      
Gross profit write Up 0.6    
New England Region Project      
Property, Plant and Equipment [Line Items]      
Gross profit write Up   0.6  
Southern California Service Project      
Property, Plant and Equipment [Line Items]      
Revision In Contract Estimates Recorded Project Write Down   0.4  
Michigan project      
Property, Plant and Equipment [Line Items]      
Gross profit write Up   1.4  
Six Projects [Member] | Southern California Construction Project      
Property, Plant and Equipment [Line Items]      
Gross profit write Up $ 3.7    
One Project [Member] | Western Pennsylvania Project [Member]      
Property, Plant and Equipment [Line Items]      
Revision In Contract Estimates Recorded Project Write Down   1.0  
One Project [Member] | Mid-Atlantic project      
Property, Plant and Equipment [Line Items]      
Revision In Contract Estimates Recorded Project Write Down   0.4  
Gross profit write Up   0.2  
One Project [Member] | New England Region Project      
Property, Plant and Equipment [Line Items]      
Gross profit write Up   3.7  
Two Projects [Member] | Mid-Atlantic project      
Property, Plant and Equipment [Line Items]      
Gross profit write Up   0.7  
Seven Projects [Member] | Construction project      
Property, Plant and Equipment [Line Items]      
Gross profit write Up   3.4  
Seven Projects [Member] | Southern California Construction Project      
Property, Plant and Equipment [Line Items]      
Revision In Contract Estimates Recorded Project Write Down   5.1  
Nine Project [Member] | Construction project      
Property, Plant and Equipment [Line Items]      
Revision In Contract Estimates Recorded Project Write Down   $ 6.5