Impacts of Derivative Financial Instruments on the Consolidated Statements of Income/(Loss) and the Consolidated Statements of Shareholders' Equity (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net						$ 16
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	[1]					327
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		$ 311		$ 507		190
Other Trading [Member] | Other Trading [Member]
Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments		61		49		61
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments		93		69		24
Other Trading [Member] | Credit Risk Contract [Member] | Other Trading [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		23		17		21
Other Trading [Member] | Equity Contract [Member] | Other Trading [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		4		4		(15)
Other Trading [Member] | Other Contract [Member] | Other Trading [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		2
Mortgage Servicing Income [Member] | Mortgage Servicing Rights [Member]
Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments		19		257		(284)
Mortgage Production Income [Member] | Loans Held For Sale [Member]
Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments		(45)		(149)		289
Mortgage Production Income [Member] | Other Contract [Member] | Loans [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		156		261		98
Other Income [Member] | Loans [Member]
Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments		(1)
Other Income [Member] | Credit Risk Contract [Member] | Loans [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		(1)		(1)		(4)
Cash Flow Hedging [Member] | Interest Income [Member] | Interest Rate Contract [Member] | forecasted debt [Member]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net						(2)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net						0
Cash Flow Hedging [Member] | Interest Income [Member] | Interest Rate Contract [Member] | Adjustable Rate Loans [Member]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net		246		99		18
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net		169	[2]	290	[3]	327	[1]
Fair Value Hedging | Interest Rate Contract [Member]
Derivative, Gain (Loss) on Derivative, Net		(2)	[4]	8	[5]
Gain (Loss) on Fair Value Hedges Recognized in Earnings		1	[4]	(7)	[5]
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net		(1)	[4]	1	[5]
Fair Value Hedging | Other Trading [Member] | Interest Rate Contract [Member] | Brokered Time Deposits [Member]
Derivative, Gain (Loss) on Derivative, Net		0		0
Gain (Loss) on Fair Value Hedges Recognized in Earnings		0		0
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net		0		0
Fair Value Hedging | Other Trading [Member] | Interest Rate Contract [Member] | Fixed Income Interest Rate [Member]
Derivative, Gain (Loss) on Derivative, Net		(2)	[4]	8	[5]	(36)	[6]
Gain (Loss) on Fair Value Hedges Recognized in Earnings		1	[4]	(7)	[5]	33	[6]
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net		$ (1)	[4]	$ 1	[5]	$ (3)	[6]

[1] During the year ended December 31, 2013, the Company also reclassified $90 million pre-tax gains from AOCI into net interest income. These gains related to hedging relationships that have been previously terminated or de-designated and are reclassified into earnings consistent with the pattern of net cash flows expected to be recognized.

[2] During the year ended December 31, 2015, the Company also reclassified $92 million of pre-tax gains from AOCI into net interest income. These gains related to hedging relationships that have been terminated or de-designated and are reclassified into earnings consistent with the pattern of net cash flows expected to be recognized.

[3] During the year ended December 31, 2014, the Company also reclassified $97 million of pre-tax gains from AOCI into net interest income. These gains related to hedging relationships that have been terminated or de-designated and are reclassified into earnings consistent with the pattern of net cash flows expected to be recognized.

[4] Amounts are recognized in trading income in the Consolidated Statements of Income.

[5] Amounts are recognized in trading income in the Consolidated Statements of Income.

[6] Amounts are recognized in trading income in the Consolidated Statements of Income.