Goodwill and Other Intangible Assets - Rollforward of Goodwill by Operating Segment (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 27,013	$ 26,098
Goodwill, Acquired During Period		912
Adjustments and other	1	3
Goodwill, Ending Balance	27,014	27,013
CB&W
Goodwill [Line Items]
Goodwill, Beginning Balance	16,865	16,870
Goodwill, Acquired During Period		0
Adjustments and other	0	(5)
Goodwill, Ending Balance	16,865	16,865
C&CB
Goodwill [Line Items]
Goodwill, Beginning Balance	6,154	6,149
Goodwill, Acquired During Period		0
Adjustments and other	216	5
Goodwill, Ending Balance	6,370	6,154
IH
Goodwill [Line Items]
Goodwill, Beginning Balance	3,994	3,079
Goodwill, Acquired During Period		912
Adjustments and other	(215)	3
Goodwill, Ending Balance	$ 3,779	$ 3,994