New Accounting Standards (Details) - USD ($) $ in Millions	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings	$ 2,436	$ 2,398	$ 4,962	$ 4,799	$ 4,366	$ 4,664	$ 4,595	$ 4,444
Accumulated other comprehensive income (loss)	(7,073)	(8,033)	(3,893)	1,553	6,544	6,944	7,561	5,840
Stockholders equity	$ 8,266	$ 6,479	$ 13,089	$ 18,300	$ 22,860	$ 23,548	$ 24,086	$ 22,203	$ 25,041
Accounting Standards Update 2018-12 [Member] | Maximum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings									2,100
Accumulated other comprehensive income (loss)									5,100
Stockholders equity									3,200
Accounting Standards Update 2018-12 [Member] | Minimum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings									1,600
Accumulated other comprehensive income (loss)									4,600
Stockholders equity									$ 2,700