v3.26.1
Fair Value Measurements (Details) - Stock Purchase and Savings Program - USD ($)
Dec. 31, 2025
Dec. 31, 2024
Fair Value Measurements    
Total assets at fair value $ 702,297,483 $ 666,372,373
Common/collective trust funds    
Fair Value Measurements    
Total assets at fair value 473,782,200 310,519,972
Mutual funds    
Fair Value Measurements    
Total assets at fair value 84,669,014 141,302,167
Non-interest bearing cash    
Fair Value Measurements    
Total assets at fair value   86,015,483
Pooled separate account    
Fair Value Measurements    
Total assets at fair value 54,870,075 66,187,003
Common stock    
Fair Value Measurements    
Total assets at fair value 70,228,611 51,125,863
Self-directed brokerage account    
Fair Value Measurements    
Total assets at fair value 18,747,583 11,221,885
Level 1    
Fair Value Measurements    
Total assets at fair value 702,297,483 666,372,373
Level 1 | Common/collective trust funds    
Fair Value Measurements    
Total assets at fair value 473,782,200 310,519,972
Level 1 | Mutual funds    
Fair Value Measurements    
Total assets at fair value 84,669,014 141,302,167
Level 1 | Non-interest bearing cash    
Fair Value Measurements    
Total assets at fair value   86,015,483
Level 1 | Pooled separate account    
Fair Value Measurements    
Total assets at fair value 54,870,075 66,187,003
Level 1 | Common stock    
Fair Value Measurements    
Total assets at fair value 70,228,611 51,125,863
Level 1 | Self-directed brokerage account    
Fair Value Measurements    
Total assets at fair value $ 18,747,583 $ 11,221,885