XML 33 R33.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Components of Gas Inventory (Detail) - USD ($)
$ in Millions
Dec. 31, 2019
Dec. 31, 2018
Public Utilities, Inventory [Line Items]    
Weighted average cost inventory amount $ 0.8 $ 0.8
Liquefied Natural Gas & Other    
Public Utilities, Inventory [Line Items]    
Weighted average cost inventory amount 0.1 0.1
Natural Gas    
Public Utilities, Inventory [Line Items]    
Weighted average cost inventory amount 0.4 0.3
Propane    
Public Utilities, Inventory [Line Items]    
Weighted average cost inventory amount $ 0.3 $ 0.4