Payment Status for the LHFI Portfolio (Detail) - USD ($) $ in Millions		Sep. 30, 2018		Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		$ 143,950		$ 139,956
Accruing 30-89 Days Past Due		1,088		1,146
Accruing 90+ Days Past Due		1,482		1,405
Financing Receivable, Recorded Investment, Nonaccrual Status	[2]	695	[1]	674	[3]
Total	[4]	147,215		143,181
Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		67,897		66,092
Accruing 30-89 Days Past Due		40		42
Accruing 90+ Days Past Due		10		7
Financing Receivable, Recorded Investment, Nonaccrual Status		256	[1]	215	[3]
Total	[5]	68,203		66,356
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		6,572		5,293
Accruing 30-89 Days Past Due		2		0
Accruing 90+ Days Past Due		1		0
Financing Receivable, Recorded Investment, Nonaccrual Status		43	[1]	24	[3]
Total		6,618		5,317
Commercial Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		3,137		3,803
Accruing 30-89 Days Past Due		0		0
Accruing 90+ Days Past Due		0		0
Financing Receivable, Recorded Investment, Nonaccrual Status		0	[1]	1	[3]
Total		3,137		3,804
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		77,606		75,188
Accruing 30-89 Days Past Due		42		42
Accruing 90+ Days Past Due		11		7
Financing Receivable, Recorded Investment, Nonaccrual Status		299	[1]	240	[3]
Total		77,958		75,477
Federal National Mortgage Association (FNMA) Insured Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		127		159
Accruing 30-89 Days Past Due		38		55
Accruing 90+ Days Past Due		287		346
Financing Receivable, Recorded Investment, Nonaccrual Status		0	[1]	0	[3]
Total		452		560
Residential Nonguaranteed [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		27,880	[6]	26,778	[7]
Accruing 30-89 Days Past Due		73	[6]	148	[7]
Accruing 90+ Days Past Due		9	[6]	4	[7]
Financing Receivable, Recorded Investment, Nonaccrual Status		225	[1],[6]	206	[3],[7]
Total	[8],[9]	28,187	[6]	27,136	[7]
Home Equity Line of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		9,449		10,348
Accruing 30-89 Days Past Due		70		75
Accruing 90+ Days Past Due		1		0
Financing Receivable, Recorded Investment, Nonaccrual Status		149	[1]	203	[3]
Total	[8]	9,669		10,626
Residential Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		185		280
Accruing 30-89 Days Past Due		1		7
Accruing 90+ Days Past Due		2		0
Financing Receivable, Recorded Investment, Nonaccrual Status		9	[1]	11	[3]
Total	[8]	197		298
Federal Family Education Loan Program (FFELP) Guaranteed Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		5,175		4,946
Accruing 30-89 Days Past Due		711		659
Accruing 90+ Days Past Due		1,153		1,028
Financing Receivable, Recorded Investment, Nonaccrual Status		0	[1],[10]	0	[3],[11]
Total		7,039		6,633
Consumer Other Direct [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		10,050		8,679
Accruing 30-89 Days Past Due		39		36
Accruing 90+ Days Past Due		4		7
Financing Receivable, Recorded Investment, Nonaccrual Status		7	[1]	7	[3]
Total		10,100		8,729
Consumer Indirect [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		11,905		12,022
Accruing 30-89 Days Past Due		99		111
Accruing 90+ Days Past Due		0		0
Financing Receivable, Recorded Investment, Nonaccrual Status		6	[1]	7	[3]
Total		12,010		12,140
Credit Card Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		1,573		1,556
Accruing 30-89 Days Past Due		15		13
Accruing 90+ Days Past Due		15		13
Financing Receivable, Recorded Investment, Nonaccrual Status		0	[1]	0	[3]
Total		1,603		1,582
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		66,344		64,768
Accruing 30-89 Days Past Due		1,046		1,104
Accruing 90+ Days Past Due		1,471		1,398
Financing Receivable, Recorded Investment, Nonaccrual Status		396	[1]	434	[3]
Total		$ 69,257		$ 67,704

[1] Includes nonaccruing LHFI past due 90 days or more of $348 million. Nonaccruing LHFI past due fewer than 90 days include nonaccrual loans modified in TDRs, performing second lien loans where the first lien loan is nonperforming, and certain energy-related commercial loans.

[2] Nonaccruing restructured loans are included in total nonaccrual loans/NPLs.

[3] Includes nonaccruing LHFI past due 90 days or more of $357 million. Nonaccruing LHFI past due fewer than 90 days include nonaccrual loans modified in TDRs, performing second lien loans where the first lien loan is nonperforming, and certain energy-related commercial loans.

[4] Includes loans of consolidated VIEs of $159 million and $179 million at September 30, 2018 and December 31, 2017, respectively.

[5] Includes $3.8 billion and $3.7 billion of lease financing, and $838 million and $778 million of installment loans at September 30, 2018 and December 31, 2017, respectively.

[6] Includes $168 million of loans measured at fair value, the majority of which were accruing current.

[7] Includes $196 million of loans measured at fair value, the majority of which were accruing current.

[8] Excludes $7.0 billion and $6.6 billion of guaranteed student loans and $452 million and $560 million of guaranteed residential mortgages at September 30, 2018 and December 31, 2017, respectively, for which there was nominal risk of principal loss due to the government guarantee.

[9] Includes $168 million and $196 million of LHFI measured at fair value at September 30, 2018 and December 31, 2017, respectively.

[10] Guaranteed loans are not placed on nonaccruing regardless of delinquency status because collection of principal and interest is reasonably assured by the government.

[11] Guaranteed loans are not placed on nonaccruing regardless of delinquency status because collection of principal and interest is reasonably assured by the government.