Quarterly report pursuant to Section 13 or 15(d)

Contingencies (Details)

v3.19.2
Contingencies (Details)
1 Months Ended 2 Months Ended 4 Months Ended 6 Months Ended
Jun. 20, 2019
USD ($)
Jan. 31, 2019
USD ($)
Feb. 01, 2018
MMBTU / d
Jan. 01, 2018
MMBTU / d
Jul. 31, 2017
MMBTU / d
Jan. 31, 2018
MMBTU / d
Nov. 30, 2017
MMBTU / d
Jun. 30, 2019
USD ($)
MMBTU / d
contract
lawsuit
Nov. 30, 2018
MMBTU / d
Jun. 30, 2018
USD ($)
Mar. 31, 2018
USD ($)
Mar. 31, 2017
USD ($)
West Virginia activities | Settled Litigation                        
Contingencies                        
Settlement amount   $ 3,150,000                    
Doddridge County, Tyler County and Ritchie County, West Virginia | Pending Litigation | Minimum                        
Contingencies                        
Damages sought                   $ 100,000    
SJGC                        
Contingencies                        
Natural gas long term purchase contract volume (in MMBtu)/day | MMBTU / d               80,000        
WGL                        
Contingencies                        
Natural gas long term purchase contract volume increase after specified events (in MMBtu)/day | MMBTU / d                 530,000      
Damages awarded $ 95,900,000                      
WGL | Pending Litigation                        
Contingencies                        
Damages sought               $ 109,000,000     $ 40,000,000  
WGL | Pending Litigation | Minimum                        
Contingencies                        
Damages sought                       $ 30,000,000
WGL - Braxton, West Virginia                        
Contingencies                        
Natural gas long term purchase contract volume (in MMBtu)/day | MMBTU / d     200,000 500,000                
WGL - Loudoun County, Virginia                        
Contingencies                        
Natural gas long term purchase contract volume increase after specified events (in MMBtu)/day | MMBTU / d                 330,000      
Potential Positive Outcome of Litigation | SJGC                        
Contingencies                        
Number of lawsuits | lawsuit               2        
Number of long term gas contracts | contract               2        
Damages sought               $ 88,000,000        
Potential Positive Outcome of Litigation | WGL                        
Contingencies                        
Natural gas long term purchase contract volume (in MMBtu)/day | MMBTU / d         500,000 500,000 600,000