Note 8 - Debt Debt, Credit Facilities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Jan. 05, 2018	Dec. 31, 2017	Oct. 30, 2017
Line of Credit Facility [Line Items]
Debt Instrument, Unamortized Discount	$ 4		$ 5
Line of Credit Facility, Current Borrowing Capacity	2,100
Loans Payable [Member] | MPC Loan Agreement [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 500
Debt Instrument, Basis Spread on Variable Rate	175.00%
Long-term Line of Credit	$ 0		0
Revolving Credit Facility | Dropdown Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	1,000
Long-term Line of Credit	300
Line of Credit Facility, Remaining Borrowing Capacity	$ 700
Line Of Credit Facility, Remaining Borrowing Capacity Percentage	70.00%
Debt, Weighted Average Interest Rate	4.14%
Revolving Credit Facility | Revolving Credit Facility
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 1,100	$ 1,100	600
Long-term Line of Credit	945		$ 423
Line of Credit Facility, Remaining Borrowing Capacity	$ 155
Line Of Credit Facility, Remaining Borrowing Capacity Percentage	14.00%
Debt, Weighted Average Interest Rate	4.33%
Revolving Credit Facility | WNRL Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				$ 500