INVENTORIES (Detail) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Inventory [Line Items]
Crude oil and feedstocks	$ 1,254.0	$ 1,074.1			$ 1,044.8
Refined products and blendstocks	1,333.5	1,328.9			1,361.7
Warehouse stock and other	135.7	120.8			109.4
Inventory, Gross	2,723.2	2,523.8			2,515.9
Lower of cost or market adjustment	(1,103.0)	(401.6)	$ (327.8)	$ (145.8)	(651.8)
Total inventories	1,620.2	2,122.2			1,864.1
Titled Inventory [Member]
Inventory [Line Items]
Crude oil and feedstocks	1,254.0	1,071.4			1,044.8
Refined products and blendstocks	1,056.3	976.0			1,026.9
Warehouse stock and other	135.7	120.8			109.4
Inventory, Gross	2,446.0	2,168.2			2,181.1
Lower of cost or market adjustment	(965.7)	(324.8)			(557.2)
Total inventories	1,480.3	1,843.4			1,623.9
Inventory Supply and off Take Arrangements [Member]
Inventory [Line Items]
Crude oil and feedstocks	0.0	2.7			0.0
Refined products and blendstocks	277.2	352.9			334.8
Warehouse stock and other	0.0	0.0			0.0
Inventory, Gross	277.2	355.6			334.8
Lower of cost or market adjustment	(137.3)	(76.8)			(94.6)
Total inventories	$ 139.9	$ 278.8			$ 240.2

Energy related inventory refined products and blend stocks.

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- Definition

The aggregate carrying amount as of the balance sheet date of unrefined petroleum and the liquid hydrocarbon components recovered from natural gas.

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Amount of inventory reserves for last-in first-out (LIFO) and other inventory valuation methods.

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Gross amount, as of the balance sheet date, of merchandise, goods, commodities, or supplies held for future sale or to be used in manufacturing, servicing or production process.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.

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Amount before valuation and LIFO reserves of other supplies used within the manufacturing or production process expected to be consumed within one year or operating cycle, if longer.

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