v3.26.3
MGE Energy Inc Consolidated Statements of Common Equity (Unaudited) - USD ($)
$ in Thousands
Total
Common Stock [Member]
Additional Paid-in Capital [Member]
Retained Earnings [Member]
AOCI Attributable to Parent [Member]
Beginning balance, value at Dec. 31, 2024 $ 1,230,138 $ 36,490 $ 429,515 $ 764,133 $ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]          
Net Income (Loss) 112,587     112,587  
Common stock dividends declared $ (50,230)     (50,230)  
Stock Issued During Period, Shares, New Issues 0        
Stock Issued During Period, Shares, Dividend Reinvestment Plan 40,995        
Issuance of common stock, net $ 3,750 41 3,709    
Equity-based compensation plans and other 1,408 11 1,397    
Ending balance, value at Sep. 30, 2025 1,297,653 36,542 434,621 826,490 0
Beginning balance, value at Jun. 30, 2025 1,269,973 36,542 434,080 799,351 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]          
Net Income (Loss) 44,497     44,497  
Common stock dividends declared $ (17,358)     (17,358)  
Stock Issued During Period, Shares, New Issues 0        
Stock Issued During Period, Shares, Dividend Reinvestment Plan 0        
Equity-based compensation plans and other $ 541   541    
Ending balance, value at Sep. 30, 2025 1,297,653 36,542 434,621 826,490 0
Beginning balance, value at Dec. 31, 2025 1,303,936 36,542 434,959 832,435 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]          
Net Income (Loss) 138,192     138,192  
Common stock dividends declared $ (54,505)     (54,505)  
Stock Issued During Period, Shares, New Issues 990,099        
Stock Issued During Period, Shares, Dividend Reinvestment Plan 111,839        
Issuance of common stock, net $ 91,979 1,256 90,723    
Equity-based compensation plans and other 1,868 22 1,846    
Ending balance, value at Sep. 30, 2026 1,481,470 37,820 527,528 916,122 0
Beginning balance, value at Jun. 30, 2026 1,440,519 37,781 523,768 878,970 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]          
Net Income (Loss) 56,358     56,358  
Common stock dividends declared $ (19,206)     (19,206)  
Stock Issued During Period, Shares, New Issues 0        
Stock Issued During Period, Shares, Dividend Reinvestment Plan 39,407        
Issuance of common stock, net $ 3,031 39 2,992    
Equity-based compensation plans and other 768   768    
Ending balance, value at Sep. 30, 2026 $ 1,481,470 $ 37,820 $ 527,528 $ 916,122 $ 0