v3.25.2
Regulatory Matters: Regulatory Matters (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Regulatory assets $ 379.9 $ 427.7
Regulatory assets, current (132.1) (154.8)
Regulatory assets, non-current 247.8 272.9
Regulatory liabilities 576.7 568.7
Regulatory liabilities, current (96.6) (94.1)
Regulatory liabilities, non-current 480.1 474.6
Deferred energy and gas costs    
Regulatory liabilities 67.5 67.8
Employee benefit plan costs and related deferred taxes    
Regulatory liabilities 35.5 36.7
Cost of removal    
Regulatory liabilities 206.6 197.0
Excess deferred income taxes    
Regulatory liabilities 234.1 238.5
Colorado renewable energy    
Regulatory liabilities 28.9 24.1
Other regulatory liabilities    
Regulatory liabilities 4.1 4.6
Storm Costs    
Regulatory assets 64.9 109.5
Deferred energy and gas costs    
Regulatory assets 70.6 62.8
Deferred gas cost adjustments    
Regulatory assets 3.0 14.5
Gas price derivatives    
Regulatory assets 1.0 2.9
Deferred taxes on AFUDC    
Regulatory assets 9.0 8.0
Employee benefit plans and related deferred taxes    
Regulatory assets 86.7 89.0
Environmental    
Regulatory assets 11.5 10.7
Loss on reacquired debt    
Regulatory assets 14.9 15.7
Deferred taxes on flow through accounting    
Regulatory assets 92.8 87.7
Decommissioning costs    
Regulatory assets 2.4 2.4
Other regulatory assets    
Regulatory assets $ 23.1 $ 24.5