XML 86 R67.htm IDEA: XBRL DOCUMENT v3.20.4
Commitment, Contingencies And Guarentees: Purchase Commitment (Details)
$ in Millions
12 Months Ended
Dec. 31, 2020
USD ($)
MMBTU
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Maximum      
Long-term Purchase Commitment [Line Items]      
We maintain natural gas supply contracts with several vendors that generally cover a period up to: 1 year    
Natural Gas, Distribution      
Long-term Purchase Commitment [Line Items]      
Natural Gas Purchases | $ $ 25.0 $ 6.7 $ 27.0
Northern Natural Gas - Ventura      
Long-term Purchase Commitment [Line Items]      
2021 3,650,000    
2022 1,810,000    
2023 1,840,000    
2024 1,820,000    
2025 0    
Thereafter 0    
Northwest Pipeline - Wyoming      
Long-term Purchase Commitment [Line Items]      
2021 1,510,000    
2022 1,510,000    
2023 1,510,000    
2024 910,000    
2025 0    
Thereafter 0    
ONEOK - Oklahoma      
Long-term Purchase Commitment [Line Items]      
2021 5,475,000    
2022 5,475,000    
2023 5,475,000    
2024 5,490,000    
2025 4,560,000    
Thereafter 0    
Southern Star Central Gas Pipeline      
Long-term Purchase Commitment [Line Items]      
2021 113,130    
2022 0    
2023 0    
2024 0    
2025 0    
Thereafter 0    
Panhandle Eastern Pipe Line      
Long-term Purchase Commitment [Line Items]      
2021 4,680    
2022 0    
2023 0    
2024 0    
2025 0    
Thereafter 0    
Gas Utilities      
Long-term Purchase Commitment [Line Items]      
Term of Evergreen Contracts 60 days