Deposits and Borrowings - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Deposits And Borrowings [Line Items]
Interest-bearing deposits	$ 211,266	$ 191,874
Domestic time deposits	19,824	12,200
Interest-bearing Deposit Liabilities, Foreign	480	843
Securitized debt obligations	18,826	16,166
Proceeds from Issuance of Secured Debt	6,259	5,062	$ 4,291
Maturities of secured debt	(3,500)
Senior and subordinated notes	23,431	21,837
Fair value hedging losses	(280)	134
Repayments of Unsecured Debt	(2,700)
Advances from Federal Home Loan Banks	17,200	20,100
Sum of investment in Federal Reserve stock used as security with Federal Reserve	1,176	1,200
Other Assets
Deposits And Borrowings [Line Items]
Federal Home Loan Bank Stock and Federal Reserve Bank Stock	1,900	2,100
Senior notes \| Total unsecured senior debt
Deposits And Borrowings [Line Items]
Proceeds from issuance of unsecured debt	4,400
Senior notes \| Floating unsecured senior debt
Deposits And Borrowings [Line Items]
Proceeds from issuance of unsecured debt	655
Senior notes \| Fixed unsecured senior debt
Deposits And Borrowings [Line Items]
Proceeds from issuance of unsecured debt	3,800
Geographic Distribution, Domestic [Member]
Deposits And Borrowings [Line Items]
Time Deposits, $100,000 or More	$ 2,875	$ 1,900

Debt Instrument, Fair Value Hedging Losses

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Deposits and borrowings.

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Secured debt maturities over the period.

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Amount of borrowings as of the balance sheet date from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and liquidity shortages.

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Amount of Federal Home Loan Bank (FHLB) and Federal Reserve Bank stock.

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Federal Reserve Bank stock represents an equity interest in the Federal Reserve Bank. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity).

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The aggregate of all domestic and foreign interest-bearing deposit liabilities.

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Amount of foreign interest-bearing deposits held by the entity.

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Amount of interest-bearing domestic time deposits. Time deposits bear interest for a fixed, stated period of time and include certificate of deposits and individual retirement accounts.

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The cash inflow from amounts received from issuance of long-term debt that is wholly or partially secured by collateral. Excludes proceeds from tax exempt secured debt.

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The cash inflow from the issuance of long-term debt that is not secured by collateral. Excludes proceeds from tax exempt unsecured debt.

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The cash outflow to repay long-term debt that is not secured by collateral. Excludes repayments of tax exempt unsecured debt.

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Carrying value as of the balance sheet date, including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.

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Amount of time deposit liabilities, including certificates of deposit, in denominations of $100,000 or more.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of uncollateralized debt obligations (with maturities initially due after one year or beyond the operating cycle if longer).

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