Composition of the Company's Loan Portfolio (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	$ 129,196	[1]	$ 127,877	[1]
Loans Held for Sale	1,488	[2]	1,699	[2]
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	65,709		64,310
Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	42,795		43,190
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	20,692		20,377
Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	58,828		57,974
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	5,961		5,481
Commercial Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	920		855
Residential Guaranteed [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	3,295		3,416
Residential Nonguaranteed [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	24,331	[3],[4]	24,412	[3],[5]
Home Equity Line of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	14,637	[3]	14,809	[3]
Residential Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	532	[3]	553	[3]
Federally Guaranteed Student Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	5,533		5,545
Consumer Other Direct [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	3,109	[6]	2,829	[6]
Consumer Indirect [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	11,339	[6]	11,272	[6]
Consumer Credit Card Financing Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	711	[6]	731	[6]
Loans Held For Investment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	129,196		127,877
Loans Held For Investment [Member] | Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	58,828		57,974
Loans Held For Investment [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	5,961		5,481
Loans Held For Investment [Member] | Commercial Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	920		855
Loans Held For Investment [Member] | Residential Guaranteed [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	3,295		3,416
Loans Held For Investment [Member] | Residential Nonguaranteed [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	24,331	[7]	24,412	[7]
Loans Held For Investment [Member] | Home Equity Line of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	14,637		14,809
Loans Held For Investment [Member] | Residential Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	532		553
Loans Held For Investment [Member] | Federally Guaranteed Student Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	5,533		5,545
Loans Held For Investment [Member] | Consumer Other Direct [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	3,109		2,829
Loans Held For Investment [Member] | Consumer Indirect [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	11,339		11,272
Loans Held For Investment [Member] | Consumer Credit Card Financing Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	711		731
Commercial Portfolio Segment [Member] | Loans | Loans Held For Investment [Member] | Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	65,709		64,310
Residential Portfolio Segment [Member] | Loans | Loans Held For Investment [Member] | Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	42,795		43,190
Consumer Portfolio Segment [Member] | Loans | Loans Held For Investment [Member] | Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	$ 20,692		$ 20,377

[1] Includes loans of consolidated VIEs of $318 million and $327 million at March 31, 2014 and December 31, 2013, respectively.

[2] Includes loans held for sale, at fair value, of consolidated VIEs of $224 million and $261 million at March 31, 2014 and December 31, 2013, respectively.

[3] Excludes $3.3 billion and $3.4 billion at March 31, 2014 and December 31, 2013, respectively, of guaranteed residential loans. At March 31, 2014 and December 31, 2013, the majority of these loans had FICO scores of 700 and above.

[4] Includes $299 million of loans carried at fair value, the majority of which were accruing current.

[5] Includes $302 million of loans carried at fair value, the majority of which were accruing current.

[6] Excludes $5.5 billion of guaranteed student loans at March 31, 2014 and December 31, 2013

[7] Includes $299 million and $302 million of loans carried at fair value at March 31, 2014 and December 31, 2013, respectively.