Composition of the Company's Loan Portfolio (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014		Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	$ 129,744	[1]	$ 127,877	[1]
Loans Held for Sale	4,046	[2],[3]	1,699	[2],[3]
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	68,538		64,310
Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	39,861		43,190
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	21,345		20,377
Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	61,337		57,974
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	6,105		5,481
Commercial Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	1,096		855
Residential Guaranteed [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	661		3,416
Residential Nonguaranteed [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	24,173	[4],[5]	24,412	[4],[6]
Home Equity Line of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	14,519	[4]	14,809	[4]
Residential Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	508	[4]	553	[4]
Federally Guaranteed Student Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	5,420		5,545
Consumer Other Direct [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	3,675	[7]	2,829	[7]
Consumer Indirect [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	11,501	[7]	11,272	[7]
Consumer Credit Card Financing Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	749	[7]	731	[7]
Loans Held For Investment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	129,744		127,877
Loans Held For Investment [Member] | Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	61,337		57,974
Loans Held For Investment [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	6,105		5,481
Loans Held For Investment [Member] | Commercial Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	1,096		855
Loans Held For Investment [Member] | Residential Guaranteed [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	661		3,416
Loans Held For Investment [Member] | Residential Nonguaranteed [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	24,173	[8]	24,412	[8]
Loans Held For Investment [Member] | Home Equity Line of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	14,519		14,809
Loans Held For Investment [Member] | Residential Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	508		553
Loans Held For Investment [Member] | Federally Guaranteed Student Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	5,420		5,545
Loans Held For Investment [Member] | Consumer Other Direct [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	3,675		2,829
Loans Held For Investment [Member] | Consumer Indirect [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	11,501		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	749		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	68,538		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	39,861		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	$ 21,345		$ 20,377

[1] Includes loans of consolidated VIEs of $307 million and $327 million at June 30, 2014 and December 31, 2013, respectively.

[2] Includes $1.4 billion of LHFS carried at fair value at both June 30, 2014 and December 31, 2013.

[3] Includes loans held for sale, at fair value, of consolidated VIEs of $0 million and $261 million at June 30, 2014 and December 31, 2013, respectively.

[4] Excludes $661 million and $3.4 billion at June 30, 2014 and December 31, 2013, respectively, of guaranteed residential loans. At June 30, 2014 and December 31, 2013, the majority of these loans had FICO scores of 700 and above.

[5] Includes $292 million of loans carried at fair value, the majority of which were accruing current.

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

[7] Excludes $5.4 billion and $5.5 billion of guaranteed student loans at June 30, 2014 and December 31, 2013, respectively.

[8] Includes $292 million and $302 million of loans carried at fair value at June 30, 2014 and December 31, 2013, respectively.