Change in Fair Value of Financial Instruments for which the FVO has been Elected (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 Trading Account Assets [Member]		Dec. 31, 2012 Trading Account Assets [Member]		Dec. 31, 2013 Trading Account Assets [Member] Trading Account Profits And Commissions [Member]	Dec. 31, 2012 Trading Account Assets [Member] Trading Account Profits And Commissions [Member]	Dec. 31, 2013 Trading Account Assets [Member] Mortgage Production Income [Member]	Dec. 31, 2012 Trading Account Assets [Member] Mortgage Production Income [Member]	Dec. 31, 2013 Trading Account Assets [Member] Mortgage Servicing Income [Member]	Dec. 31, 2012 Trading Account Assets [Member] Mortgage Servicing Income [Member]	Dec. 31, 2013 Loans Held For Sale [Member]		Dec. 31, 2012 Loans Held For Sale [Member]		Dec. 31, 2013 Loans Held For Sale [Member] Trading Account Profits And Commissions [Member]	Dec. 31, 2012 Loans Held For Sale [Member] Trading Account Profits And Commissions [Member]	Dec. 31, 2013 Loans Held For Sale [Member] Mortgage Production Income [Member]		Dec. 31, 2012 Loans Held For Sale [Member] Mortgage Production Income [Member]		Dec. 31, 2013 Loans Held For Sale [Member] Mortgage Servicing Income [Member]	Dec. 31, 2012 Loans Held For Sale [Member] Mortgage Servicing Income [Member]	Dec. 31, 2013 Loans Held For Investment [Member]		Dec. 31, 2012 Loans Held For Investment [Member]		Dec. 31, 2013 Loans Held For Investment [Member] Trading Account Profits And Commissions [Member]	Dec. 31, 2012 Loans Held For Investment [Member] Trading Account Profits And Commissions [Member]	Dec. 31, 2013 Loans Held For Investment [Member] Mortgage Production Income [Member]		Dec. 31, 2012 Loans Held For Investment [Member] Mortgage Production Income [Member]		Dec. 31, 2013 Loans Held For Investment [Member] Mortgage Servicing Income [Member]	Dec. 31, 2012 Loans Held For Investment [Member] Mortgage Servicing Income [Member]	Dec. 31, 2013 Mortgage Servicing Rights [Member]		Dec. 31, 2012 Mortgage Servicing Rights [Member]		Dec. 31, 2013 Mortgage Servicing Rights [Member] Trading Account Profits And Commissions [Member]	Dec. 31, 2012 Mortgage Servicing Rights [Member] Trading Account Profits And Commissions [Member]	Dec. 31, 2013 Mortgage Servicing Rights [Member] Mortgage Production Income [Member]		Dec. 31, 2012 Mortgage Servicing Rights [Member] Mortgage Production Income [Member]		Dec. 31, 2013 Mortgage Servicing Rights [Member] Mortgage Servicing Income [Member]	Dec. 31, 2012 Mortgage Servicing Rights [Member] Mortgage Servicing Income [Member]	Dec. 31, 2013 Brokered Deposits [Member]		Dec. 31, 2012 Brokered Deposits [Member]		Dec. 31, 2013 Brokered Deposits [Member] Trading Account Profits And Commissions [Member]	Dec. 31, 2012 Brokered Deposits [Member] Trading Account Profits And Commissions [Member]	Dec. 31, 2013 Brokered Deposits [Member] Mortgage Production Income [Member]	Dec. 31, 2012 Brokered Deposits [Member] Mortgage Production Income [Member]	Dec. 31, 2013 Brokered Deposits [Member] Mortgage Servicing Income [Member]	Dec. 31, 2012 Brokered Deposits [Member] Mortgage Servicing Income [Member]	Dec. 31, 2013 Long-term Debt [Member]		Dec. 31, 2012 Long-term Debt [Member]		Dec. 31, 2013 Long-term Debt [Member] Trading Account Profits And Commissions [Member]	Dec. 31, 2012 Long-term Debt [Member] Trading Account Profits And Commissions [Member]	Dec. 31, 2013 Long-term Debt [Member] Mortgage Production Income [Member]	Dec. 31, 2012 Long-term Debt [Member] Mortgage Production Income [Member]	Dec. 31, 2013 Long-term Debt [Member] Mortgage Servicing Income [Member]	Dec. 31, 2012 Long-term Debt [Member] Mortgage Servicing Income [Member]	Dec. 31, 2011 Brokered Deposits [Member]		Dec. 31, 2011 Mortgage Servicing Rights [Member]		Dec. 31, 2011 Loans Held For Investment [Member]		Dec. 31, 2011 Loans Held For Sale [Member]		Dec. 31, 2011 Trading Account Assets [Member]		Dec. 31, 2011 Long-term Debt [Member]		Dec. 31, 2011 Mortgage Production Income [Member] Brokered Deposits [Member]		Dec. 31, 2011 Mortgage Production Income [Member] Mortgage Servicing Rights [Member]		Dec. 31, 2011 Mortgage Production Income [Member] Loans Held For Investment [Member]		Dec. 31, 2011 Mortgage Production Income [Member] Loans Held For Sale [Member]		Dec. 31, 2011 Mortgage Production Income [Member] Trading Account Assets [Member]		Dec. 31, 2011 Mortgage Production Income [Member] Long-term Debt [Member]		Dec. 31, 2011 Mortgage Servicing Income [Member] Brokered Deposits [Member]	Dec. 31, 2011 Mortgage Servicing Income [Member] Mortgage Servicing Rights [Member]	Dec. 31, 2011 Mortgage Servicing Income [Member] Loans Held For Investment [Member]	Dec. 31, 2011 Mortgage Servicing Income [Member] Loans Held For Sale [Member]	Dec. 31, 2011 Mortgage Servicing Income [Member] Trading Account Assets [Member]	Dec. 31, 2011 Mortgage Servicing Income [Member] Long-term Debt [Member]	Dec. 31, 2011 Trading Account Profits And Commissions [Member] Brokered Deposits [Member]	Dec. 31, 2011 Trading Account Profits And Commissions [Member] Mortgage Servicing Rights [Member]	Dec. 31, 2011 Trading Account Profits And Commissions [Member] Loans Held For Investment [Member]	Dec. 31, 2011 Trading Account Profits And Commissions [Member] Loans Held For Sale [Member]	Dec. 31, 2011 Trading Account Profits And Commissions [Member] Trading Account Assets [Member]	Dec. 31, 2011 Trading Account Profits And Commissions [Member] Long-term Debt [Member]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	$ 13	[1]	$ 8	[2]	$ 13	$ 8	$ 0	$ 0	$ 0	$ 0	$ (134)	[1]	$ 171	[2]	$ 1	$ 10	$ (135)	[3]	$ 161	[4]	$ 0	$ 0	$ (10)	[1]	$ 21	[2]	$ 0	$ 1	$ (10)	[3]	$ 20	[4]	$ 0	$ 0	$ 54	[1]	$ (322)	[2]	$ 0	$ 0	$ 4	[3]	$ 31	[4]	$ 50	$ (353)	$ 8	[1]	$ 5	[2]	$ 8	$ 5	$ 0	$ 0	$ 0	$ 0	$ 36	[1]	$ (65)	[2]	$ 36	$ (65)	$ 0	$ 0	$ 0	$ 0	$ 32	[5]	$ (726)	[5]	$ 14	[5]	$ 169	[5]	$ 21	[5]	$ (12)	[5]	$ 0	[6]	$ 7	[6]	$ 11	[6]	$ 179	[6]	$ 0	[6]	$ 0	[6]	$ 0	$ (733)	$ 0	$ 0	$ 0	$ 0	$ 32	$ 0	$ 3	$ (10)	$ 21	$ (12)

[1] Changes in fair value for the year ended December 31, 2013 exclude accrued interest for the period then ended. Interest income or interest expense on trading loans, LHFS, LHFI, brokered time deposits, and long-term debt that have been elected to be carried at fair value are recognized in interest income or interest expense in the Consolidated Statements of Income.

[2] Changes in fair value for the year ended December 31, 2012 exclude accrued interest for the period then ended. Interest income or interest expense on trading loans, LHFS, LHFI, brokered time deposits, and long-term debt that have been elected to be carried at fair value are recognized in interest income or interest expense in the Consolidated Statements of Income.

[3] Income related to LHFS does not include income from IRLCs. For the year ended December 31, 2013, income related to MSRs includes MSRs recognized upon the sale of loans reported at LOCOM.

[4] 1 Income related to LHFS does not include income from IRLCs. For the year ended December 31, 2012, income related to MSRs includes MSRs recognized upon the sale of loans reported at LOCOM.

[5] 2 Changes in fair value for the year ended December 31, 2011 exclude accrued interest for the period then ended. Interest income or interest expense on trading loans, LHFS, LHFI, brokered time deposits, and long-term debt that have been elected to be carried at fair value are recognized in interest income or interest expense in the Consolidated Statements of Income.

[6] 1 Income related to LHFS does not include income from IRLCs. For the year ended December 31, 2011, income related to MSRs includes MSRs recognized upon the sale of loans reported at LOCOM.