Financial Instruments Gain (Loss) Recognized on Derivatives Not Designated as Hedging Table (Details) - Net gain from investment activities - Not designated as hedging instrument - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivatives not designated as hedging instruments recognized in income	[1]	$ 206	$ (603)
Equity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivatives not designated as hedging instruments recognized in income	[1]	58	(573)
Credit contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivatives not designated as hedging instruments recognized in income	[1]	53	(25)
Commodity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivatives not designated as hedging instruments recognized in income	[1]	$ 95	$ (5)

[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 other income (loss), net for all other segments.