Investments (Net Unrealized Gains Losses on Investments) (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Gain (Loss) on Securities [Line Items]
Net unrealized gains (losses) on investments	$ (34,532)	$ (25,026)
Fixed maturities | Available-for-sale | With an allowance
Gain (Loss) on Securities [Line Items]
Net unrealized gains (losses) on investments	(95)	(45)
Fixed maturities | Available-for-sale | Without an allowance
Gain (Loss) on Securities [Line Items]
Net unrealized gains (losses) on investments	(36,383)	(27,545)
Derivatives designated as cash flow hedges
Gain (Loss) on Securities [Line Items]
Net unrealized gains (losses) on investments	1,947	2,616
Derivatives designated as fair value hedges
Gain (Loss) on Securities [Line Items]
Net unrealized gains (losses) on investments	(18)	(54)
Other investments
Gain (Loss) on Securities [Line Items]
Net unrealized gains (losses) on investments	17	$ 2
Other investments | Available-for-sale
Gain (Loss) on Securities [Line Items]
Net unrealized gains (losses) on investments	$ 136