Payment Status for the LHFI Portfolio (Detail) - USD ($) $ in Millions		Dec. 31, 2017		Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		$ 139,956		$ 140,130
Accruing 30-89 Days Past Due		1,146		1,035
Accruing 90+ Days Past Due		1,405		1,288
Financing Receivable, Recorded Investment, Nonaccrual Status	[2]	674	[1]	845	[3]
Total	[4]	143,181		143,298
Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		66,092		68,776
Accruing 30-89 Days Past Due		42		35
Accruing 90+ Days Past Due		7		12
Financing Receivable, Recorded Investment, Nonaccrual Status		215	[1]	390	[3]
Total	[5]	66,356		69,213
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		5,293		4,988
Accruing 30-89 Days Past Due		0		1
Accruing 90+ Days Past Due		0		0
Financing Receivable, Recorded Investment, Nonaccrual Status		24	[1]	7	[3]
Total		5,317		4,996
Commercial Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		3,803		3,998
Accruing 30-89 Days Past Due		0		0
Accruing 90+ Days Past Due		0		0
Financing Receivable, Recorded Investment, Nonaccrual Status		1	[1]	17	[3]
Total		3,804		4,015
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		75,188		77,762
Accruing 30-89 Days Past Due		42		36
Accruing 90+ Days Past Due		7		12
Financing Receivable, Recorded Investment, Nonaccrual Status		240	[1]	414	[3]
Total		75,477		78,224
Federal National Mortgage Association (FNMA) Insured Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		159		155
Accruing 30-89 Days Past Due		55		55
Accruing 90+ Days Past Due		346		327
Financing Receivable, Recorded Investment, Nonaccrual Status		0	[1]	0	[3]
Total		560		537
Residential Nonguaranteed [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		26,778	[6]	25,869	[7]
Accruing 30-89 Days Past Due		148	[6]	84	[7]
Accruing 90+ Days Past Due		4	[6]	7	[7]
Financing Receivable, Recorded Investment, Nonaccrual Status		206	[1],[6]	177	[3],[7]
Total	[8],[9]	27,136	[6]	26,137	[7]
Home Equity Line of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		10,348		11,596
Accruing 30-89 Days Past Due		75		81
Accruing 90+ Days Past Due		0		0
Financing Receivable, Recorded Investment, Nonaccrual Status		203	[1]	235	[3]
Total	[8]	10,626		11,912
Residential Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		280		389
Accruing 30-89 Days Past Due		7		3
Accruing 90+ Days Past Due		0		0
Financing Receivable, Recorded Investment, Nonaccrual Status		11	[1]	12	[3]
Total	[8]	298		404
Federal Family Education Loan Program (FFELP) Guaranteed Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		4,946		4,637
Accruing 30-89 Days Past Due		659		603
Accruing 90+ Days Past Due		1,028		927
Financing Receivable, Recorded Investment, Nonaccrual Status		0	[1]	0	[3]
Total		6,633		6,167
Consumer Other Direct [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		8,679		7,726
Accruing 30-89 Days Past Due		36		35
Accruing 90+ Days Past Due		7		4
Financing Receivable, Recorded Investment, Nonaccrual Status		7	[1]	6	[3]
Total		8,729		7,771
Consumer Indirect [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		12,022		10,608
Accruing 30-89 Days Past Due		111		126
Accruing 90+ Days Past Due		0		1
Financing Receivable, Recorded Investment, Nonaccrual Status		7	[1]	1	[3]
Total		12,140		10,736
Credit Card Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		1,556		1,388
Accruing 30-89 Days Past Due		13		12
Accruing 90+ Days Past Due		13		10
Financing Receivable, Recorded Investment, Nonaccrual Status		0	[1]	0	[3]
Total		1,582		1,410
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Current		64,768		62,368
Accruing 30-89 Days Past Due		1,104		999
Accruing 90+ Days Past Due		1,398		1,276
Financing Receivable, Recorded Investment, Nonaccrual Status		434	[1]	431	[3]
Total		$ 67,704		$ 65,074

[1] Nonaccruing loans past due 90 days or more totaled $357 million. Nonaccruing loans 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] Nonaccruing loans past due 90 days or more totaled $360 million. Nonaccruing loans 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 $179 million and $211 million at December 31, 2017 and December 31, 2016, respectively.

[5] Includes $3.7 billion of lease financing at both December 31, 2017 and 2016, and $778 million and $729 million of installment loans at December 31, 2017 and 2016, respectively.

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

[7] Includes $222 million of loans measured at fair value, the majority of which were accruing current.

[8] Excludes $6.6 billion and $6.2 billion of guaranteed student loans and $560 million and $537 million of guaranteed residential mortgages at December 31, 2017 and 2016, respectively, for which there was nominal risk of principal loss due to the government guarantee.

[9] Includes $196 million and $222 million of LHFI measured at fair value at December 31, 2017 and 2016, respectively.