Fair Value Measurements - Changes in balances of Level 3 financial liabilities carried at fair value (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial liabilities, Beginning Balance	$ (23)	$ (3,954)	$ (23)	$ (3,933)
Total realized/unrealized gains (losses) included in Net income	0	(183)	0	(222)
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	0	0	0	0
Purchases and issuances	0	(72)	0	(146)
Sales and settlements	0	66	0	158
Transfer into Level 3	0	0	0	0
Transfer out of Level 3	0	0	0	0
Sale of annuity business		4,143		4,143
Financial liabilities, Ending Balance	(23)	0	(23)	0
Contingent consideration — acquisitions
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial liabilities, Beginning Balance	(23)		(23)
Total realized/unrealized gains (losses) included in Net income	0		0
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	0		0
Purchases and issuances	0		0
Sales and settlements	0		0
Transfer into Level 3	0		0
Transfer out of Level 3	0		0
Financial liabilities, Ending Balance	$ (23)		$ (23)
Liabilities of discontinued annuity operations | Annuity subsidiaries
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial liabilities, Beginning Balance		(3,954)		(3,933)
Total realized/unrealized gains (losses) included in Net income		(183)		(222)
Total realized/unrealized gains (losses) included in other comprehensive income (loss)		0		0
Purchases and issuances		(72)		(146)
Sales and settlements		66		158
Transfer into Level 3		0		0
Transfer out of Level 3		0		0
Sale of annuity business		4,143		4,143
Financial liabilities, Ending Balance		$ 0		$ 0