Commitments, Guarantees, Contingent Liabilities, and Related Parties (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Guarantor Obligations [Line Items]
Commitments to extend credit expiring in one year	$ 7,300
Standby letters of credit expiring in one year	433
Standby letters of credit, thereafter	409
Letters of credit, accrued liability	4
Reserve for unfunded lending commitments	2
Deferred commitment fees	2
Risk-weighted values assigned to all off-balance sheet financial and derivative instruments	9,000	$ 8,500
Minimum
Guarantor Obligations [Line Items]
Estimate of possible losses	0
Maximum
Guarantor Obligations [Line Items]
Estimate of possible losses	$ 40