Quarterly report pursuant to Section 13 or 15(d)

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

v3.8.0.1
Other Non-Current Assets - Equity Method Investments (Details)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2017
USD ($)
Sep. 30, 2016
USD ($)
Sep. 30, 2017
USD ($)
mi
Sep. 30, 2016
USD ($)
Dec. 31, 2016
USD ($)
Investment [Line Items]          
Equity method investment $ 64   $ 64   $ 10
Other—related party 1 $ 0 2 $ 0  
Accounts receivable—related party 1   1   $ 0
Midship Holdings [Member]          
Investment [Line Items]          
Equity method investment 55   55    
O&M Services [Member] | Midship Pipeline [Member] | Service Agreements [Member]          
Investment [Line Items]          
Other—related party 1   2    
Accounts receivable—related party 1   $ 1    
CCL [Member] | Midship Pipeline [Member] | Natural Gas Transportation Agreement [Member]          
Investment [Line Items]          
Long-term Purchase Commitment, Period     10 years    
EIG [Member] | Maximum [Member]          
Investment [Line Items]          
Investment Company, Financial Commitment to Investee, Future Amount $ 500   $ 500    
Midship Pipeline [Member]          
Investment [Line Items]          
Length Of Natural Gas Pipeline | mi     230