Branch Assets and Liabilities Held for Sale Groups - Disposal Group (Details) - USD ($)		3 Months Ended		6 Months Ended
		Dec. 31, 2021	Jun. 30, 2021	Dec. 31, 2021	Dec. 31, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale	[1]	$ 4,217,000,000		$ 4,217,000,000	$ 337,000,000
Other branch related assets held for sale:
Total other branch related assets held for sale	[1]	249,000,000		249,000,000	0
Deposits held for sale		8,750,000,000		8,750,000,000	0	[1]
Other branch related liabilities held for sale:
Total other branch related liabilities held for sale	[1]	152,000,000		152,000,000	0
Reduction to the provision for credit losses		22,000,000
Exit of Mass Market Retail Banking Business and Remaining Retail Credit Card Portfolio
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
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:
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale		461,000,000		461,000,000	129,000,000
Commercial loans: | Exit of Mass Market Retail Banking Business and Remaining Retail Credit Card Portfolio
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale		79,000,000	149,000,000	79,000,000
Other branch related liabilities held for sale:
Lower of amortized cost or fair value adjustment			0
Reduction to the provision for credit losses			0
Consumer loans:
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale		3,756,000,000		3,756,000,000	208,000,000
Other branch related liabilities held for sale:
Reduction to the provision for credit losses		22,000,000
Consumer loans: | Exit of Mass Market Retail Banking Business and Remaining Retail Credit Card Portfolio
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale		3,681,000,000	3,616,000,000	3,681,000,000
Other branch related liabilities held for sale:
Lower of amortized cost or fair value adjustment			0	7,000,000
Reduction to the provision for credit losses			100,000,000
Consumer loans: | Residential mortgages
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale		3,082,000,000		3,082,000,000	208,000,000
Consumer loans: | Residential mortgages | Exit of Mass Market Retail Banking Business and Remaining Retail Credit Card Portfolio
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale		3,007,000,000	2,364,000,000	3,007,000,000
Consumer loans: | Home Equity Mortgages
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale		275,000,000		275,000,000	0
Consumer loans: | Home Equity Mortgages | Exit of Mass Market Retail Banking Business and Remaining Retail Credit Card Portfolio
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale		275,000,000	265,000,000	275,000,000
Consumer loans: | Credit cards
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale		195,000,000		195,000,000	0
Consumer loans: | Credit cards | Exit of Mass Market Retail Banking Business and Remaining Retail Credit Card Portfolio
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale		195,000,000	829,000,000	195,000,000
Consumer loans: | Other consumer
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale		204,000,000		204,000,000	$ 0
Consumer loans: | Other consumer | Exit of Mass Market Retail Banking Business and Remaining Retail Credit Card Portfolio
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale		204,000,000	$ 158,000,000	204,000,000
Retail Branches Sold
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale		2,441,000,000		2,441,000,000
Other branch related assets held for sale:
Lease ROU assets		151,000,000		151,000,000
Properties and equipment, net		40,000,000		40,000,000
Cash and other assets		58,000,000		58,000,000
Total other branch related assets held for sale		249,000,000		249,000,000
Total branch assets held for sale		2,690,000,000		2,690,000,000
Deposits held for sale		8,750,000,000		8,750,000,000
Other branch related liabilities held for sale:
Lease liabilities		144,000,000		144,000,000
Other liabilities		8,000,000		8,000,000
Total other branch related liabilities held for sale		152,000,000		152,000,000
Total branch liabilities held for sale		8,902,000,000		8,902,000,000
Retail Branches Sold | Residential mortgages
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale		1,845,000,000		1,845,000,000
Retail Branches Sold | Home Equity Mortgages
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale		217,000,000		217,000,000
Retail Branches Sold | Credit cards
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale		178,000,000		178,000,000
Retail Branches Sold | Other consumer
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale		129,000,000		129,000,000
Retail Branches Sold | Commercial loans:
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans held for sale		$ 72,000,000		$ 72,000,000

[1] The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") at December 31, 2021 and 2020. Assets and liabilities exclude intercompany balances that eliminate in consolidation. See Note 27, "Variable Interest Entities," for additional information. At December 31,20212020(in millions)AssetsLoans$46 $10 Other assets55 79 Total assets$101 $89 LiabilitiesInterest, taxes and other liabilities$9 $10 Total liabilities$9 $10