Branch Assets and Liabilities Held for Sale Groups - Disposal Group (Details) - USD ($)		3 Months Ended	9 Months Ended
		Jun. 30, 2021	Sep. 30, 2021	Dec. 31, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale			$ 4,927,000,000	$ 337,000,000
Other branch related assets held for sale:
Total other branch related assets held for sale			244,000,000	0
Deposits held for sale			9,321,000,000	0
Other branch related liabilities held for sale:
Total other branch related liabilities held for sale			160,000,000	0
Lease, ROU assets, excluding amounts transferred to held-for-sale			225,000,000
Lease liabilities, excluding amounts transferred to held-for-sale			325,000,000
Exit of Mass Market Retail Banking Business and Remaining Retail Credit Card Portfolio [Member]
Other branch related liabilities held for sale:
Lower of amortized cost or fair value adjustment		$ 0
Reduction to the provision for credit losses		101,000,000
Credit Cards [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale		1,100,000,000
Commercial Loans [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale			1,291,000,000	129,000,000
Commercial Loans [Member] | Exit of Mass Market Retail Banking Business and Remaining Retail Credit Card Portfolio [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale		149,000,000	105,000,000
Other branch related liabilities held for sale:
Lower of amortized cost or fair value adjustment		0
Consumer Loans [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale			3,636,000,000	208,000,000
Consumer Loans [Member] | Exit of Mass Market Retail Banking Business and Remaining Retail Credit Card Portfolio [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale		3,616,000,000	3,584,000,000
Other branch related liabilities held for sale:
Lower of amortized cost or fair value adjustment		0
Reduction to the provision for credit losses		100,000,000	100,000,000
Consumer Loans [Member] | Residential Mortgage [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale			2,449,000,000	208,000,000
Consumer Loans [Member] | Residential Mortgage [Member] | Exit of Mass Market Retail Banking Business and Remaining Retail Credit Card Portfolio [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale		2,364,000,000	2,397,000,000
Consumer Loans [Member] | Home Equity Mortgages [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale			257,000,000	0
Consumer Loans [Member] | Home Equity Mortgages [Member] | Exit of Mass Market Retail Banking Business and Remaining Retail Credit Card Portfolio [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale		265,000,000	257,000,000
Consumer Loans [Member] | Credit Cards [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale			785,000,000	0
Consumer Loans [Member] | Credit Cards [Member] | Exit of Mass Market Retail Banking Business and Remaining Retail Credit Card Portfolio [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale		829,000,000	785,000,000
Consumer Loans [Member] | Other Consumer [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale			145,000,000	$ 0
Consumer Loans [Member] | Other Consumer [Member] | Exit of Mass Market Retail Banking Business and Remaining Retail Credit Card Portfolio [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale		$ 158,000,000	145,000,000
Retail Branches Sold [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale	[1]		2,610,000,000
Other branch related assets held for sale:
Lease ROU assets	[2]		149,000,000
Properties and equipment, net			40,000,000
Cash and other assets			55,000,000
Total other branch related assets held for sale			244,000,000
Total branch assets held for sale	[3]		2,854,000,000
Deposits held for sale			9,321,000,000
Other branch related liabilities held for sale:
Lease liabilities	[2]		151,000,000
Other liabilities			9,000,000
Total other branch related liabilities held for sale			160,000,000
Total branch liabilities held for sale	[3]		9,481,000,000
Retail Branches Sold [Member] | Residential Mortgage [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale			1,952,000,000
Retail Branches Sold [Member] | Home Equity Mortgages [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale			235,000,000
Retail Branches Sold [Member] | Credit Cards [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale			182,000,000
Retail Branches Sold [Member] | Other Consumer [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale			142,000,000
Retail Branches Sold [Member] | Commercial Loans [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale			$ 99,000,000

[1] Includes $99 million of commercial loans, $1,952 million of residential mortgage loans, $235 million of home equity mortgage loans, $182 million of credit card loans and $142 million of other consumer loans

[2] At September 30, 2021, our lease ROU assets and lease liabilities, excluding the amounts transferred to held for sale, totaled $225 million and $325 million, respectively.

[3] 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.