Derivatives - Gains and Losses on Derivatives (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Losses on interest rate swaps and warrants, net	$ (585)	$ 0
Oil Collars and Calls | Net sales
Derivative Instruments, Gain (Loss) [Line Items]
Losses on interest rate swaps and warrants, net	952	0
Marketing Derivatives | Net sales
Derivative Instruments, Gain (Loss) [Line Items]
Losses on interest rate swaps and warrants, net	410	564
Interest Rate Swaps | Losses on interest rate swaps and warrants, net
Derivative Instruments, Gain (Loss) [Line Items]
Losses on interest rate swaps and warrants, net	(669)	0
Warrants | Losses on interest rate swaps and warrants, net
Derivative Instruments, Gain (Loss) [Line Items]
Losses on interest rate swaps and warrants, net	$ 84	$ 0