XML 61 R45.htm IDEA: XBRL DOCUMENT v3.24.0.1
Organization, Business and Significant Accounting Policies (Details)
 12 Months Ended
Dec. 31, 2023
USD ($)
segment
$ / shares
Dec. 31, 2022
USD ($)
$ / shares
Dec. 31, 2021
USD ($)
$ / shares
Organization Consolidation and Presentation of Financial Statements [Line Items]      
Number of business segments (segment) | segment 2    
Contract retention provision 10.00%    
Contract revenues $ 3,643,905,000 $ 3,008,542,000 $ 2,498,289,000
Foreign currency gain (loss) 0 0 (100,000)
Revenue recognized, related to change orders and claims included as contract price adjustments 76,500,000 19,600,000  
Increase (decrease) in operating income 129,093,000 114,907,000 118,560,000
Increase (decrease) in net income $ 90,990,000 $ 83,381,000 $ 85,010,000
Increase (decrease) in diluted earnings per common share (in dollars per share) | $ / shares $ 5.40 $ 4.91 $ 4.95
Advertising cost $ 1,800,000 $ 1,200,000 $ 800,000
Option to extend lease term (up to) 6 years    
Option to terminate leases, period 1 year    
Government assistance, amount   $ 2,300,000  
Government Assistance, Statement of Income or Comprehensive Income [Extensible Enumeration]   Other Nonoperating Income (Expense)  
Revenue from Contract with Customer | Top Ten Customers | Customer Concentration Risk      
Organization Consolidation and Presentation of Financial Statements [Line Items]      
Concentration risk 37.90% 35.40% 34.90%
Labor employees covered by collective bargaining agreements | Labor Force Concentration Risk      
Organization Consolidation and Presentation of Financial Statements [Line Items]      
Concentration risk 84.00%    
Contingencies Excluding Wildfire and Health Insurance      
Organization Consolidation and Presentation of Financial Statements [Line Items]      
Insurance coverage deductible $ 1,000,000    
Health Insurance      
Organization Consolidation and Presentation of Financial Statements [Line Items]      
Insurance coverage deductible $ 200,000    
Minimum      
Organization Consolidation and Presentation of Financial Statements [Line Items]      
Remaining lease term 1 year    
Maximum      
Organization Consolidation and Presentation of Financial Statements [Line Items]      
Remaining lease term 10 years    
Contracts Accounted for under Percentage of Completion      
Organization Consolidation and Presentation of Financial Statements [Line Items]      
Increase (decrease) in consolidated gross margin (1.70%) (0.40%) 0.40%
Increase (decrease) in operating income $ (62,200,000) $ (9,800,000) $ 9,200,000
Increase (decrease) in net income $ (43,600,000) $ (6,900,000) $ 6,600,000
Increase (decrease) in diluted earnings per common share (in dollars per share) | $ / shares $ (2.59) $ (0.41) $ 0.39
Joint Venture      
Organization Consolidation and Presentation of Financial Statements [Line Items]      
Contract revenues $ 33,000,000 $ 11,300,000 $ 26,100,000