Quarterly report pursuant to Section 13 or 15(d)

Other Non-Current Assets - Equity Method Investments (Details)

v3.19.1
Other Non-Current Assets - Equity Method Investments (Details)
3 Months Ended
Mar. 31, 2019
USD ($)
mi
Mar. 31, 2018
USD ($)
Dec. 31, 2018
USD ($)
May 31, 2018
USD ($)
Investment [Line Items]        
Equity method investment $ 117,000,000   $ 94,000,000  
Accounts receivable—related party 3,000,000   4,000,000  
Midship Holdings [Member]        
Investment [Line Items]        
Equity method investment 108,000,000   85,000,000  
O&M Services [Member] | Midship Pipeline [Member] | Service Agreements [Member]        
Investment [Line Items]        
Other revenues—related party 4,000,000 $ 1,000,000    
Accounts receivable—related party $ 3,000,000   $ 4,000,000  
CCL [Member] | Midship Pipeline [Member] | Natural Gas Transportation Agreement [Member]        
Investment [Line Items]        
Long-term Purchase Commitment, Period 10 years      
Midship Pipeline [Member]        
Investment [Line Items]        
Length of Natural Gas Pipeline | mi 200      
Midship Pipeline [Member] | CCL [Member] | Midship Pipeline Letter of Credit [Member]        
Investment [Line Items]        
Letter of Credit, Maximum Borrowing Capacity       $ 16,000,000
Letters of credit issued $ 0