XML 48 R36.htm IDEA: XBRL DOCUMENT v3.20.1
Derivative Instruments (Details)
$ in Thousands
3 Months Ended
Mar. 31, 2020
USD ($)
MWh
Dec. 31, 2019
USD ($)
Mar. 31, 2019
USD ($)
Commodity Contract      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]      
Fair value at end of the period $ 4,300    
GOLDEN STATE WATER COMPANY      
Derivative Instruments, Gain (Loss) [Line Items]      
Description of derivative activity volume | MWh 594,392    
GOLDEN STATE WATER COMPANY | Commodity Contract      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]      
Fair value at beginning of the period $ (3,171)   $ (311)
Unrealized loss on purchased power contracts (1,109)   (25)
Fair value at end of the period $ (4,280) $ (3,171) $ (336)
GOLDEN STATE WATER COMPANY | Minimum | Commodity Contract      
Derivative Instruments, Gain (Loss) [Line Items]      
Term of derivative contract   3 years  
GOLDEN STATE WATER COMPANY | Maximum | Commodity Contract      
Derivative Instruments, Gain (Loss) [Line Items]      
Term of derivative contract   5 years