Loans and Allowance for Credit Losses: Loans and Unfunded Credit Commitments - Allowance for Credit Losses: Unfunded Credit Commitments (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Financing Receivable, Allowance for Credit Loss [Line Items]
Change in allowance for credit loss	$ 12
Allowance for credit loss, beginning balance	545	$ 396	$ 422	$ 448
Provision for (reduction in) credit losses	30	(9)	184	41
Foreign currency translation adjustments	(3)		(6)
Allowance for credit loss, ending balance	557	398	557	398
Unfunded Credit Commitments
Financing Receivable, Allowance for Credit Loss [Line Items]
Change in allowance for credit loss	41
Allowance for credit loss, beginning balance	224	120	171	121
Provision for (reduction in) credit losses	42	29	96	28
Foreign currency translation adjustments	(1)	0	(2)	0
Allowance for credit loss, ending balance	$ 265	$ 149	$ 265	$ 149

Amount of gain (loss) from converting allowance reserve for credit loss to currency of reporting entity from amount denominated or measured in a different currency, which decreases (increases) the allowance for loan and lease losses.

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Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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Amount of increase (decrease) in allowance for credit loss on financing receivable.

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Amount of credit loss expense (reversal of expense) for financing receivable.

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