Financial Instruments Gain (Loss) Recognized on Derivatives Not Designated as Hedging Table (Details) - Not designated as hedging instrument - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivatives not designated as hedging instruments recognized in income	[1]	$ (1,163)	$ 206
Equity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivatives not designated as hedging instruments recognized in income	[1]	(1,101)	58
Credit contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivatives not designated as hedging instruments recognized in income	[1]	(64)	53
Commodity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivatives not designated as hedging instruments recognized in income	[1]	2	95
Investment Segment | Net gain from investment activities
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivatives not designated as hedging instruments recognized in income	[1]	(1,179)	147
Energy Segment | Cost of goods sold
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivatives not designated as hedging instruments recognized in income	[1]	$ 16	$ 59

[1] Gains (losses) recognized on derivatives are classified in net gain (loss) from investment activities in our condensed consolidated statements of operations for our Investment segment and are included in cost of goods sold for our Energy segment. (Losses) gains recognized on derivatives for our Investment segment were $(1,179) million and $147 million for the three months ended March 31, 2019 and 2018, respectively. Gains recognized on derivatives for our Energy segment were $16 million and $59 million for the three months ended March 31, 2019 and 2018, respectively.