Quarterly report pursuant to Section 13 or 15(d)

Transportation and Distribution Revenue - Additional Information (Details)

v3.20.2
Transportation and Distribution Revenue - Additional Information (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended 143 Months Ended
Jun. 30, 2020
Jun. 30, 2019
Jun. 30, 2020
Jun. 30, 2019
Oct. 31, 2030
Dec. 31, 2019
Concentration Risk [Line Items]            
Remaining performance obligation $ 55,400   $ 55,400      
Contract asset balance $ 33   $ 33     $ 206
Natural gas transportation contracts | Product and services | Revenue            
Concentration Risk [Line Items]            
Concentration percentage 68.00% 57.60% 68.40% 59.50%    
Natural gas distribution contracts | Product and services | Revenue            
Concentration Risk [Line Items]            
Concentration percentage 27.20% 35.00% 25.00% 34.90%    
Forecast            
Concentration Risk [Line Items]            
Recognized performance obligations quarterly         $ 138