Price Risk Management Activities (Details) bu in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($) bu MBbls	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Price Risk Management Activities (Textual)
Compliance program costs | $	$ 58,933	$ 96,476	$ 104,732
Environmental Compliance Program Price Risk [Member]
Price Risk Management Activities (Textual)
Compliance program costs | $	$ 648	$ 318	$ 536
Derivatives Designated as Economic Hedges [Member] | Futures, 2021 Maturity [Member] | Long (Purchases) [Member] | Crude Oil and Refined Petroleum Products (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	53,205
Derivatives Designated as Economic Hedges [Member] | Futures, 2021 Maturity [Member] | Long (Purchases) [Member] | Corn (in thousands of bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume | bu	49,840
Derivatives Designated as Economic Hedges [Member] | Futures, 2021 Maturity [Member] | Short (Sales) [Member] | Crude Oil and Refined Petroleum Products (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	50,518
Derivatives Designated as Economic Hedges [Member] | Futures, 2021 Maturity [Member] | Short (Sales) [Member] | Corn (in thousands of bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume | bu	78,135
Derivatives Designated as Economic Hedges [Member] | Futures, 2022 Maturity [Member] | Long (Purchases) [Member] | Crude Oil and Refined Petroleum Products (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	1
Derivatives Designated as Economic Hedges [Member] | Futures, 2022 Maturity [Member] | Long (Purchases) [Member] | Corn (in thousands of bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume | bu	10
Derivatives Designated as Economic Hedges [Member] | Futures, 2022 Maturity [Member] | Short (Sales) [Member] | Crude Oil and Refined Petroleum Products (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	0
Derivatives Designated as Economic Hedges [Member] | Futures, 2022 Maturity [Member] | Short (Sales) [Member] | Corn (in thousands of bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume | bu	155
Derivatives Designated as Economic Hedges [Member] | Physical Contracts, 2021 Maturity [Member] | Long (Purchases) [Member] | Corn (in thousands of bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume | bu	27,144
Derivatives Designated as Economic Hedges [Member] | Physical Contracts, 2022 Maturity [Member] | Long (Purchases) [Member] | Corn (in thousands of bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume | bu	145
Derivatives Designated as Economic Hedges [Member] | Foreign Exchange Contract, US Dollars [Member]
Price Risk Management Activities (Textual)
Monetary notional amount of derivative liabilities | $	$ 325
Derivatives Designated as Economic Hedges [Member] | Foreign Exchange Contract, US Dollar Equivalent Canadian Dollars [Member]
Price Risk Management Activities (Textual)
Monetary notional amount of derivative liabilities | $	1,600
Derivatives Designated as Economic Hedges [Member] | Foreign Exchange Contract, Maturity on or Before February 16, 2021 [Member]
Price Risk Management Activities (Textual)
Monetary notional amount of derivative liabilities | $	1,100
Derivatives Designated as Economic Hedges [Member] | Foreign Exchange Contract, Maturity by April 15, 2021 [Member]
Price Risk Management Activities (Textual)
Monetary notional amount of derivative liabilities | $	$ 800
Cash Flow Hedges [Member] | Derivatives Designated as Hedges [Member] | Futures, 2021 Maturity [Member] | Long (Purchases) [Member] | Refined Petroleum Products (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	334
Cash Flow Hedges [Member] | Derivatives Designated as Hedges [Member] | Futures, 2021 Maturity [Member] | Short (Sales) [Member] | Refined Petroleum Products (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	1,364
Cash Flow Hedges [Member] | Derivatives Designated as Hedges [Member] | Futures, 2022 Maturity [Member] | Long (Purchases) [Member] | Refined Petroleum Products (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	0
Cash Flow Hedges [Member] | Derivatives Designated as Hedges [Member] | Futures, 2022 Maturity [Member] | Short (Sales) [Member] | Refined Petroleum Products (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	0