Fair Value Measurements - Gains or losses recorded related to fair value option (Details) - Fair Value Option - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Fair Value, Option, Quantitative Disclosures
Fair value option gain (loss)	$ (229)	$ 444	$ (501)	$ 1,319
Other bond securities
Fair Value, Option, Quantitative Disclosures
Fair value option gain (loss)	(241)	35	(915)	32
Alternative investments
Fair Value, Option, Quantitative Disclosures
Fair value option gain (loss)	(57)	403	174	1,248
Long-term debt
Fair Value, Option, Quantitative Disclosures
Fair value option gain (loss)	$ 69	$ 6	$ 240	$ 39