Annual report pursuant to Section 13 and 15(d)

Construction Contract and Other Service Revenues (Remaining Performance Obligations) (Details)

v3.20.4
Construction Contract and Other Service Revenues (Remaining Performance Obligations) (Details) - Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
$ in Millions
Dec. 31, 2020
USD ($)
Revenue from Contract with Customer [Abstract]  
Remaining performance obligations $ 81.9
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]  
Expected timing 1 year