XML 143 R124.htm IDEA: XBRL DOCUMENT v3.20.4
Income Taxes: Tax Cut and Jobs Act (Details) - USD ($)
$ in Thousands
 12 Months Ended 36 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2020
Tax Cuts and Jobs Act of 2017, Change in Tax Rate, Regulatory Liability     $ 309,000  
Increase (Decrease) in Regulatory Liabilities $ (10,706) $ (15,158) 18,533  
Deferred Income Tax Charge        
Tax Cuts and Jobs Act of 2017, Change in Tax Rate, Regulatory Liability     301,000  
Increase (Decrease) in Regulatory Liabilities     $ 11,000  
Revenue Subject to Refund        
Revenue Refunded To Customers As A Result Of The TCJA Tax Benefits       $ 13,300