Branch Assets and Liabilities Held for Sale (Details)		1 Months Ended	3 Months Ended		9 Months Ended
		May 31, 2021 branch	Sep. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Sep. 30, 2021 USD ($)
Restructuring Cost and Reserve [Line Items]
Revenues associated with the disposal group as percent of consolidated revenues (percent)			7.00%		7.00%
Retail Branches Sold [Member]
Restructuring Cost and Reserve [Line Items]
Assets held for sale	[1]		$ 2,854,000,000		$ 2,854,000,000
Liabilities held for sale	[1]		$ 9,481,000,000		$ 9,481,000,000
Rebranding of Retail Branches [Member] | Minimum [Member]
Restructuring Cost and Reserve [Line Items]
Number of bank branches | branch		20
Rebranding of Retail Branches [Member] | Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Number of bank branches | branch		25
Exit of Mass Market Retail Banking Business [Member]
Restructuring Cost and Reserve [Line Items]
Number of branches sold | branch		90
Assets held for sale				$ 2,900,000,000
Liabilities held for sale				10,100,000,000
Lower of amortized cost or fair value adjustment				0
Exit of Mass Market Retail Banking Business and Remaining Retail Credit Card Portfolio [Member]
Restructuring Cost and Reserve [Line Items]
Lower of amortized cost or fair value adjustment				$ 0

[1] The sale of this disposal group is expected to result in a net cash payment as the liabilities being assumed are greater than the assets being purchased.