v3.26.1
Revenue (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Disaggregation of Revenue [Line Items]    
Total Operating Revenues $ 347,026 $ 337,353
Total Operating Revenues from Contracts with Customers 342,859 337,335
Electric    
Disaggregation of Revenue [Line Items]    
Total Operating Revenues 165,870 149,720
Electric Segment - ARP Revenues 4,167 18
Manufacturing    
Disaggregation of Revenue [Line Items]    
Total Operating Revenues 89,559 81,685
Plastics    
Disaggregation of Revenue [Line Items]    
Total Operating Revenues 91,597 105,948
Total Retail | Electric    
Disaggregation of Revenue [Line Items]    
Total Operating Revenues 149,236 133,373
Retail: Residential | Electric    
Disaggregation of Revenue [Line Items]    
Total Operating Revenues 46,010 43,257
Retail: Commercial and Industrial | Electric    
Disaggregation of Revenue [Line Items]    
Total Operating Revenues 100,987 87,889
Retail: Other | Electric    
Disaggregation of Revenue [Line Items]    
Total Operating Revenues 2,239 2,227
Transmission | Electric    
Disaggregation of Revenue [Line Items]    
Total Operating Revenues 13,451 12,130
Wholesale | Electric    
Disaggregation of Revenue [Line Items]    
Total Operating Revenues 1,503 2,778
Other | Electric    
Disaggregation of Revenue [Line Items]    
Total Operating Revenues 1,680 1,439
Metal Parts and Tooling | Manufacturing    
Disaggregation of Revenue [Line Items]    
Total Operating Revenues 77,643 70,870
Plastic Products and Tooling | Manufacturing    
Disaggregation of Revenue [Line Items]    
Total Operating Revenues 9,841 8,959
Scrap Metal | Manufacturing    
Disaggregation of Revenue [Line Items]    
Total Operating Revenues $ 2,075 $ 1,856