XML 46 R35.htm IDEA: XBRL DOCUMENT v3.22.0.1
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)
 12 Months Ended
Dec. 31, 2021
Accounting Policies [Abstract]  
Schedule of inventory Our inventory as of December 31 consisted of:
(in millions)20212020
Materials and supplies$50.5 $45.8 
Natural gas in storage33.5 18.9 
Fossil fuel28.9 28.0 
Total$112.9 $92.7 
Schedule of AFUDC amounts
We recorded the following AFUDC for the years ended December 31:
(in millions)202120202019
AFUDC – Debt
$3.5 $4.6 $2.4 
AFUDC – Equity
9.0 11.8 5.7 
Schedule of assumptions used to estimate the fair value of stock options granted The following table shows the estimated weighted-average fair value per stock option granted to our employees along with the weighted-average assumptions used in the valuation models:
202120202019
Stock options granted18,021 22,042 21,638 
Estimated weighted-average fair value per stock option$13.20 $10.82 $8.60 
Assumptions used to value the options:
Risk-free interest rate
0.1% – 0.9%
1.6% – 1.9%
2.5% – 2.7%
Dividend yield2.9 %3.0 %3.6 %
Expected volatility21.0 %16.0 %17.0 %
Expected life (years)8.78.68.5