Fair Value Measurements - Gains or losses recorded related to fair value option (Details) - Fair Value Option - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Fair Value, Option, Quantitative Disclosures
Fair value option gain (loss)	$ (373)	$ 1,704	$ 1,061
Other bond securities
Fair Value, Option, Quantitative Disclosures
Fair value option gain (loss)	(822)	(12)	552
Alternative investments
Fair Value, Option, Quantitative Disclosures
Fair value option gain (loss)	224	1,650	685
Long-term debt
Fair Value, Option, Quantitative Disclosures
Fair value option gain (loss)	$ 225	$ 66	$ (176)