XML 77 R41.htm IDEA: XBRL DOCUMENT v3.20.1
Significant Accounting Policies, Allowance for Funds Used During Construction (Details)
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Allowance for Funds Used During Construction [Abstract]    
PPUC approved rate for AFUDC 10.04% 10.04%