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, 2016		Dec. 31, 2015		Dec. 31, 2014
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ 440		$ 311		$ 507
Other Trading [Member] | Other Trading [Member]
Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments	51		61		49
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments	101		93		69
Other Trading [Member] | Credit Risk Contract [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	19		23		17
Other Trading [Member] | Equity Contract [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	4		4		4
Other Trading [Member] | Other Contract [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	3		2
Mortgage Servicing Income [Member] | Mortgage Servicing Rights [Member]
Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments	62		19		257
Mortgage Production Income [Member] | Loans [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	210		156		261
Mortgage Production Income [Member] | Loans Held For Sale [Member]
Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments	(6)		(45)		(149)
Other Income [Member] | Loans [Member]
Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments	(1)		(1)
Other Income [Member] | Credit Risk Contract [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(3)		(1)		(1)
Cash Flow Hedging [Member] | Interest Income [Member] | Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	(145)		246		99
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	147	[1]	169	[2]	290	[3]
Fair Value Hedging [Member] | Other Trading [Member]
Derivative, Gain (Loss) on Derivative, Net	(87)		(2)		8
Gain (Loss) on Fair Value Hedges Recognized in Earnings	89		1		(7)
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net	2		(1)		1
Fair Value Hedging [Member] | Other Trading [Member] | Fixed Income Interest Rate [Member]
Derivative, Gain (Loss) on Derivative, Net	(87)	[4]	(2)	[5]	8	[6]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	89	[4]	1	[5]	(7)	[6]
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net	2	[4]	(1)	[5]	$ 1	[6]
Fair Value Hedging [Member] | Other Trading [Member] | Brokered Time Deposits [Member]
Derivative, Gain (Loss) on Derivative, Net	0	[4]	0	[5]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	0	[4]	0	[5]
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net	$ 0	[4]	$ 0	[5]

[1] During the year ended December 31, 2016, 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.

[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 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.

[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.