Basis of Presentation - Effects of Adoption of ASU 2018-12, Stockholders' Equity (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity	$ 15,314	$ 15,201	$ 16,576	$ 17,471
As Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity		15,478		19,175
Accumulated Other Comprehensive Income (Loss)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity	(3,062)	(3,320)	(2,216)	(1,320)	$ (1,516)
Accumulated Other Comprehensive Income (Loss) | As Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity		(3,284)		186	581
Accumulated Other Comprehensive Income (Loss) | De-recognition of shadow reserves
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity					2,331
Accumulated Other Comprehensive Income (Loss) | Re-measurement of LFPB using an upper-medium grade fixed income instrument yield discount rate
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity					(4,428)
Accumulated Other Comprehensive Income (Loss) | Other adjustments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity	15,293	14,931	15,059	14,754	14,145
Retained Earnings | As Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity		15,144		14,776	14,150
Retained Earnings | De-recognition of shadow reserves
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity
Retained Earnings | Re-measurement of LFPB using an upper-medium grade fixed income instrument yield discount rate
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity
Retained Earnings | Other adjustments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity					(5)
Noncontrolling Interests
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity	$ 863	852	$ 1,004	1,153	1,077
Noncontrolling Interests | As Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity		$ 880		$ 1,329	1,321
Noncontrolling Interests | De-recognition of shadow reserves
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity					270
Noncontrolling Interests | Re-measurement of LFPB using an upper-medium grade fixed income instrument yield discount rate
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity					(513)
Noncontrolling Interests | Other adjustments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity					$ (1)