XML 70 R54.htm IDEA: XBRL DOCUMENT v3.20.4
Equity Method Investments - Narrative (Details) - USD ($)
$ in Thousands
1 Months Ended 12 Months Ended
Feb. 10, 2020
Nov. 30, 2019
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Feb. 28, 2014
Apr. 30, 2012
Schedule of Equity Method Investments [Line Items]                
Well costs     $ 0 $ 0 $ 0 $ 19,511    
Payments for sale of equity method investments     9,424          
Net proceeds from sale of investment       249,463 $ 0      
Restricted cash     $ 11,578 13,556        
Transcontinental Gas Pipe Line Company LLC                
Schedule of Equity Method Investments [Line Items]                
Entity's equity interest in construction agreement (as a percent)             61.00%  
Meade Pipeline Co LLC                
Schedule of Equity Method Investments [Line Items]                
Entity's equity interest in construction agreement (as a percent)             39.00%  
Constitution Pipeline Company, LLC                
Schedule of Equity Method Investments [Line Items]                
Ownership interest 25.00%             25.00%
Payable for disposal of equity method investment       $ 9,400        
Payments for sale of equity method investments $ 9,400              
Meade Pipeline Co LLC                
Schedule of Equity Method Investments [Line Items]                
Ownership interest             20.00%  
Net proceeds from sale of investment   $ 249,500            
Gain on sale of investment   $ 75,800