Derivatives - Open Commodity Derivative Contracts (Details) - Exchange Traded gal in Thousands, bbl in Thousands	3 Months Ended
	Mar. 31, 2020 bbl gal
Crude oil
Derivative [Line Items]
Percentage of derivative contracts expiring in the period	94.80%
Crude oil | Long
Derivative [Line Items]
Notional contracts (in thousands of Total Barrels)	29,202	[1]
Crude oil | Long | Spread Contracts
Derivative [Line Items]
Notional contracts (in thousands of Total Barrels)	3,840
Crude oil | Short
Derivative [Line Items]
Notional contracts (in thousands of Total Barrels) | gal	46,121	[1]
Crude oil | Short | Spread Contracts
Derivative [Line Items]
Notional contracts (in thousands of Total Barrels)	640
Refined products
Derivative [Line Items]
Percentage of derivative contracts expiring in the period	84.30%
Refined products | Long
Derivative [Line Items]
Notional contracts (in thousands of Total Barrels)	20,370	[1]
Refined products | Long | Spread Contracts
Derivative [Line Items]
Notional contracts (in thousands of Total Barrels)	2,575
Refined products | Short
Derivative [Line Items]
Notional contracts (in thousands of Total Barrels) | gal	16,960	[1]
Refined products | Short | Spread Contracts
Derivative [Line Items]
Notional contracts (in thousands of Total Barrels)	1,775
Blending products
Derivative [Line Items]
Percentage of derivative contracts expiring in the period	100.00%
Blending products | Long
Derivative [Line Items]
Notional contracts (in thousands of Total Barrels)	3,581	[1]
Blending products | Short
Derivative [Line Items]
Notional contracts (in thousands of Total Barrels) | gal	3,359	[1]

[1] Included in exchange-traded are spread contracts in thousands of barrels: Crude oil - 3,840 long and 640 short; Refined products - 2,575 long and 1,775 short