Price Risk Management Activities (Details) lb in Thousands, bu in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($) MMBTU lb MBbls bu	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Price Risk Management Activities (Textual)
Compliance program costs | $	$ 104,732	$ 83,037	$ 65,962
Environmental Compliance Program Price Risk [Member]
Price Risk Management Activities (Textual)
Compliance program costs | $	536	$ 942	$ 749
Foreign Currency Contracts [Member]
Price Risk Management Activities (Textual)
Monetary notional amount of derivative liabilities | $	$ 441
Foreign currency commitments maturity date	Jan. 31, 2019
Economic Hedges [Member] | Future, 2019 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	149,470
Economic Hedges [Member] | Future, 2019 Maturity [Member] | Long (Purchases) [Member] | Natural Gas (in millions of British thermal units) [Member]
Volume of Outstanding Contracts
Derivative, nonmonetary notional amount, energy measure | MMBTU	5,000,000
Economic Hedges [Member] | Future, 2019 Maturity [Member] | Long (Purchases) [Member] | Corn (in bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume | bu	26,025
Economic Hedges [Member] | Future, 2019 Maturity [Member] | Long (Purchases) [Member] | Soybean Oil (in pounds) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, mass | lb	137,518
Economic Hedges [Member] | Future, 2019 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	143,826
Economic Hedges [Member] | Future, 2019 Maturity [Member] | Short (Sales) [Member] | Corn (in bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume | bu	55,395
Economic Hedges [Member] | Future, 2019 Maturity [Member] | Short (Sales) [Member] | Soybean Oil (in pounds) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, mass | lb	285,957
Economic Hedges [Member] | Future, 2020 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	224
Economic Hedges [Member] | Future, 2020 Maturity [Member] | Long (Purchases) [Member] | Natural Gas (in millions of British thermal units) [Member]
Volume of Outstanding Contracts
Derivative, nonmonetary notional amount, energy measure | MMBTU	0
Economic Hedges [Member] | Future, 2020 Maturity [Member] | Long (Purchases) [Member] | Corn (in bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume | bu	0
Economic Hedges [Member] | Future, 2020 Maturity [Member] | Long (Purchases) [Member] | Soybean Oil (in pounds) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, mass | lb	0
Economic Hedges [Member] | Future, 2020 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	671
Economic Hedges [Member] | Future, 2020 Maturity [Member] | Short (Sales) [Member] | Corn (in bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume | bu	875
Economic Hedges [Member] | Future, 2020 Maturity [Member] | Short (Sales) [Member] | Soybean Oil (in pounds) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, mass | lb	0
Economic Hedges [Member] | Options, 2019 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	26,500
Economic Hedges [Member] | Options, 2019 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	26,500
Economic Hedges [Member] | Options, 2020 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	0
Economic Hedges [Member] | Options, 2020 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
Economic Hedges [Member] | Physical Contracts, 2019 Maturity [Member] | Long (Purchases) [Member] | Corn (in bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume | bu	27,109
Economic Hedges [Member] | Physical Contracts, 2020 Maturity [Member] | Long (Purchases) [Member] | Corn (in bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume | bu	875