XML 141 R111.htm IDEA: XBRL DOCUMENT v3.25.0.1
Stockholders' Equity (Details) - USD ($)
$ in Thousands
 12 Months Ended
May 03, 2024
Dec. 31, 2024
Dec. 31, 2023
Class of Stock [Line Items]      
Total capitalization   $ 2,612,233 $ 2,267,065
OTP      
Class of Stock [Line Items]      
Equity to total capitalization ratio (as a percent)   53.10%  
Net assets restricted from distribution   $ 834,500  
Minimum | Minnesota Public Utilities Commission | OTP      
Class of Stock [Line Items]      
Public utilities, requested equity capital structure (as a percent)   47.20%  
Maximum | OTP      
Class of Stock [Line Items]      
Total capitalization   $ 2,200,000  
Maximum | Minnesota Public Utilities Commission | OTP      
Class of Stock [Line Items]      
Public utilities, requested equity capital structure (as a percent)   57.70%  
Second Shelf Registration      
Class of Stock [Line Items]      
Shelf registration (in shares) 1,500,000    
Number of shares issued (in shares)   70,469  
Number of shares available for grant (in shares)   1,429,531  
Cumulative Preferred Shares      
Class of Stock [Line Items]      
Preferred stock, shares authorized (in shares)   1,500,000  
Preferred stock, shares outstanding (in shares)   0 0
Cumulative Preference Shares      
Class of Stock [Line Items]      
Preferred stock, shares authorized (in shares)   1,000,000  
Preferred stock, shares outstanding (in shares)   0 0