Goodwill and Mortgage Servicing Rights - Goodwill Changes During Period (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Goodwill [Roll Forward]
Balance at beginning of period	$ 50,298,000,000	$ 49,243,000,000	$ 50,315,000,000	$ 49,248,000,000	$ 49,248,000,000
Changes during the period from:
Business combinations	470,000,000	0	470,000,000	0
Other	(71,000,000)	13,000,000	(88,000,000)	8,000,000
Balance at end of period	$ 50,697,000,000	$ 49,256,000,000	50,697,000,000	$ 49,256,000,000	50,315,000,000
Goodwill impairment			$ 0		$ 0