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Construction Contracts - Summary of Backlog (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Revenue, Remaining Performance Obligation [Roll Forward]    
Beginning backlog $ 71,258 $ 242,622
New contracts/change orders 3,124 40,440
Work performed (35,544) (47,420)
Ending backlog $ 38,838 $ 235,642
Minimum | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01    
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]    
Expected completion of contracts 12 months  
Maximum | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01    
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]    
Expected completion of contracts 18 months