Goodwill and Other Intangible Assets - Rollforward of Goodwill by Operating Segment (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 26,098	$ 24,447
Goodwill, Acquired During Period	187	1,724
Adjustments and other	14	(73)
Goodwill, Ending Balance	26,299	26,098
CB&W
Goodwill [Line Items]
Goodwill, Beginning Balance	16,870	15,841
Goodwill, Acquired During Period	0	1,168
Adjustments and other	0	(139)
Goodwill, Ending Balance	16,870	16,870
C&CB
Goodwill [Line Items]
Goodwill, Beginning Balance	6,149	6,167
Goodwill, Acquired During Period	0	0
Adjustments and other	0	(18)
Goodwill, Ending Balance	6,149	6,149
IH
Goodwill [Line Items]
Goodwill, Beginning Balance	3,079	2,439
Goodwill, Acquired During Period	187	556
Adjustments and other	14	84
Goodwill, Ending Balance	$ 3,280	$ 3,079