Financial Instruments Derivative Activities Table (Details) - Investment Segment - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Equity Contract [Member]
Primary underlying risk:
Notional Exposure of Derivatives, Long Position	$ 806	$ 118
Short Notional Exposure	13,113	8,368
Credit Risk Contract [Member]
Primary underlying risk:
Notional Exposure of Derivatives, Long Position	0	0
Short Notional Exposure	622	479
Commodity Contract [Member]
Primary underlying risk:
Notional Exposure of Derivatives, Long Position	0	0
Short Notional Exposure	0	114
Credit Default Swap [Member]
Primary underlying risk:
Derivative, Notional Amount	$ 4,700	$ 1,800