v3.8.0.1
Debt Credit Facilities (Details)
$ in Millions
 9 Months Ended
Sep. 30, 2017
USD ($)
Line of Credit Facility [Line Items]  
Line of Credit Facility, Current Borrowing Capacity $ 2,100
Long-term Line of Credit 55
Letters of Credit Outstanding, Amount 1
Line of Credit Facility, Remaining Borrowing Capacity 2,044
Line of Credit Facility, Maximum Borrowing Capacity 2,300
Andeavor Logistics Revolving Credit Facility (a)  
Line of Credit Facility [Line Items]  
Line of Credit Facility, Current Borrowing Capacity 600 [1]
Long-term Line of Credit 35 [1]
Letters of Credit Outstanding, Amount 0 [1]
Line of Credit Facility, Remaining Borrowing Capacity $ 565 [1]
Line of Credit Facility, Expiration Date Jan. 29, 2021 [1]
Andeavor Logistics Dropdown Credit Facility  
Line of Credit Facility [Line Items]  
Line of Credit Facility, Current Borrowing Capacity $ 1,000
Long-term Line of Credit 0
Letters of Credit Outstanding, Amount 0
Line of Credit Facility, Remaining Borrowing Capacity $ 1,000
Line of Credit Facility, Expiration Date Jan. 29, 2021
WNRL Revolving Credit Facility [Member]  
Line of Credit Facility [Line Items]  
Line of Credit Facility, Current Borrowing Capacity $ 500
Long-term Line of Credit 20
Bridge Loan 10
Letters of Credit Outstanding, Amount 1
Line of Credit Facility, Remaining Borrowing Capacity $ 479
Line of Credit Facility, Expiration Date Oct. 16, 2018
Debt, Weighted Average Interest Rate 3.24%
Debt Instrument, Interest Rate, Effective Percentage 3.50%
Andeavor Logistics Revolving Credit Facility [Domain]  
Line of Credit Facility [Line Items]  
Debt, Weighted Average Interest Rate 3.49%
Maximum [Member] | WNRL Revolving Credit Facility [Member]  
Line of Credit Facility [Line Items]  
Long-term Line of Credit $ 25
Debt Instrument, Basis Spread on Variable Rate 0.75%
eurodollar rate (LIBOR) 1.75%
Minimum | WNRL Revolving Credit Facility [Member]  
Line of Credit Facility [Line Items]  
Debt Instrument, Basis Spread on Variable Rate 1.75%
eurodollar rate (LIBOR) 2.75%
Western Refining Logistics  
Line of Credit Facility [Line Items]  
Long-term Debt, Fair Value $ 25
[1] The weighted average interest rates for borrowings under the Andeavor Logistics Revolving Credit Facility and the WNRL Revolving Credit Facility were 3.49% and 3.24%, respectively, at September 30, 2017.