Fair Value Measurements (Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Detail) - USD ($) $ in Millions		Mar. 31, 2017		Dec. 31, 2016
Assets:
Available-for-sale securities, fair value	[1]	$ 31,531		$ 31,183
Trading securities		689		410
Fair value, recurring
Assets:
Available-for-sale securities, fair value		30,923	[2]	30,576	[3]
Trading securities		689		410
Residential mortgage loans held for sale		606		686
Residential mortgage loans measured at FV	[4]	141	[5]	143
Mortgage servicing rights	[6]	776
Derivative assets	[7]	846		1,057
Total assets		33,981		32,872
Liabilities:
Derivative liabilities	[8]	489		666
Short positions	[8]	27		21
Total liabilities		516		687
Interest Rate Contract | Fair value, recurring
Assets:
Derivative assets		641		748
Liabilities:
Derivative liabilities		189		265
Foreign Exchange Contract | Fair value, recurring
Assets:
Derivative assets		126		202
Liabilities:
Derivative liabilities		123		204
Equity Contract | Fair value, recurring
Assets:
Derivative assets		0		0
Liabilities:
Derivative liabilities		97		91
Commodity Contract | Fair value, recurring
Assets:
Derivative assets		79		107
Liabilities:
Derivative liabilities		80		106
U.S. Treasury and federal agencies
Assets:
Available-for-sale securities, fair value		437		549
U.S. Treasury and federal agencies | Fair value, recurring
Assets:
Available-for-sale securities, fair value		437		549
Trading securities		18		23
Obligations of states and political subdivisions
Assets:
Available-for-sale securities, fair value		45		45
Obligations of states and political subdivisions | Fair value, recurring
Assets:
Available-for-sale securities, fair value		45		45
Trading securities		21		39
Agency mortgage-backed securities | Residential mortgage backed securities
Assets:
Available-for-sale securities, fair value		16,245	[9]	15,608	[10]
Agency mortgage-backed securities | Residential mortgage backed securities | Fair value, recurring
Assets:
Available-for-sale securities, fair value		16,245		15,608
Trading securities		265		8
Agency mortgage-backed securities | Commercial mortgage backed securities
Assets:
Available-for-sale securities, fair value		8,672		9,055
Agency mortgage-backed securities | Commercial mortgage backed securities | Fair value, recurring
Assets:
Available-for-sale securities, fair value		8,672		9,055
Non-agency mortgage-backed securities | Commercial mortgage backed securities
Assets:
Available-for-sale securities, fair value		3,299		3,112
Non-agency mortgage-backed securities | Commercial mortgage backed securities | Fair value, recurring
Assets:
Available-for-sale securities, fair value		3,299		3,112
Asset-backed securities and other debt securities
Assets:
Available-for-sale securities, fair value		2,134		2,116
Asset-backed securities and other debt securities | Fair value, recurring
Assets:
Available-for-sale securities, fair value		2,134		2,116
Trading securities		24		15
Equity securities
Assets:
Available-for-sale securities, fair value		699	[11]	698	[12]
Equity securities | Fair value, recurring
Assets:
Available-for-sale securities, fair value		91	[2]	91	[3]
Trading securities		361		325
Fair Value, Inputs, Level 1 | Fair value, recurring
Assets:
Available-for-sale securities, fair value		527	[2],[13]	561	[3],[14]
Trading securities		361	[13]	325	[14]
Derivative assets	[7]	24	[13]	42	[14]
Total assets		912	[13]	928	[14]
Liabilities:
Derivative liabilities	[8]	13	[13]	30	[14]
Short positions	[8]	21	[13]	17	[14]
Total liabilities		34	[13]	47	[14]
Fair Value, Inputs, Level 1 | Interest Rate Contract | Fair value, recurring
Assets:
Derivative assets		1	[13]	20	[14]
Liabilities:
Derivative liabilities		5	[13]	3	[14]
Fair Value, Inputs, Level 1 | Commodity Contract | Fair value, recurring
Assets:
Derivative assets		23	[13]	22	[14]
Liabilities:
Derivative liabilities		8	[13]	27	[14]
Fair Value, Inputs, Level 1 | U.S. Treasury and federal agencies | Fair value, recurring
Assets:
Available-for-sale securities, fair value		437	[13]	471	[14]
Fair Value, Inputs, Level 1 | Equity securities | Fair value, recurring
Assets:
Available-for-sale securities, fair value		90	[2],[13]	90	[3],[14]
Trading securities		361	[13]	325	[14]
Fair Value, Inputs, Level 2 | Fair value, recurring
Assets:
Available-for-sale securities, fair value		30,396	[2],[13]	30,015	[3],[14]
Trading securities		328	[13]	85	[14]
Residential mortgage loans held for sale		606	[13]	686	[14]
Derivative assets	[7]	806	[13]	1,002	[14]
Total assets		32,136	[13]	31,788	[14]
Liabilities:
Derivative liabilities	[8]	374	[13]	540	[14]
Short positions	[8]	6	[13]	4	[14]
Total liabilities		380	[13]	544	[14]
Fair Value, Inputs, Level 2 | Interest Rate Contract | Fair value, recurring
Assets:
Derivative assets		624	[13]	715	[14]
Liabilities:
Derivative liabilities		179	[13]	257	[14]
Fair Value, Inputs, Level 2 | Foreign Exchange Contract | Fair value, recurring
Assets:
Derivative assets		126	[13]	202	[14]
Liabilities:
Derivative liabilities		123	[13]	204	[14]
Fair Value, Inputs, Level 2 | Commodity Contract | Fair value, recurring
Assets:
Derivative assets		56	[13]	85	[14]
Liabilities:
Derivative liabilities		72	[13]	79	[14]
Fair Value, Inputs, Level 2 | U.S. Treasury and federal agencies | Fair value, recurring
Assets:
Available-for-sale securities, fair value		0	[13]	78	[14]
Trading securities		18	[13]	23	[14]
Fair Value, Inputs, Level 2 | Obligations of states and political subdivisions | Fair value, recurring
Assets:
Available-for-sale securities, fair value		45	[13]	45	[14]
Trading securities		21	[13]	39	[14]
Fair Value, Inputs, Level 2 | Agency mortgage-backed securities | Residential mortgage backed securities | Fair value, recurring
Assets:
Available-for-sale securities, fair value		16,245	[13]	15,608	[14]
Trading securities		265	[13]	8	[14]
Fair Value, Inputs, Level 2 | Agency mortgage-backed securities | Commercial mortgage backed securities | Fair value, recurring
Assets:
Available-for-sale securities, fair value		8,672	[13]	9,055	[14]
Fair Value, Inputs, Level 2 | Non-agency mortgage-backed securities | Commercial mortgage backed securities | Fair value, recurring
Assets:
Available-for-sale securities, fair value		3,299	[13]	3,112	[14]
Fair Value, Inputs, Level 2 | Asset-backed securities and other debt securities | Fair value, recurring
Assets:
Available-for-sale securities, fair value		2,134	[13]	2,116	[14]
Trading securities		24	[13]	15	[14]
Fair Value, Inputs, Level 2 | Equity securities | Fair value, recurring
Assets:
Available-for-sale securities, fair value		1	[2],[13]	1	[3],[14]
Fair Value, Inputs, Level 3 | Fair value, recurring
Assets:
Residential mortgage loans measured at FV	[4]	141	[5]	143
Mortgage servicing rights	[6]	776
Derivative assets	[7]	16		13
Total assets		933		156
Liabilities:
Derivative liabilities	[8]	102		96
Total liabilities		102		96
Fair Value, Inputs, Level 3 | Interest Rate Contract | Fair value, recurring
Assets:
Derivative assets		16		13
Liabilities:
Derivative liabilities		5		5
Fair Value, Inputs, Level 3 | Equity Contract | Fair value, recurring
Assets:
Derivative assets		0		0
Liabilities:
Derivative liabilities		$ 97		$ 91

[1] Amortized cost of $ 31,348 and $ 31,024 at March 31, 2017 and December 31, 2016 , respectively.

[2] Excludes FHLB, FRB and DTCC restricted stock holdings totaling $ 248 , $ 359 and $ 1 , respectively, at March 31, 2017 .

[3] Excludes FHLB, FRB and DTCC restricted stock holdings totaling $248, $358 and $1 , respectively, at December 31, 2016 .

[4] Includes residential mortgage loans originated as held for sale and subsequently transferred to held for investment.

[5] Includes residential mortgage loans originated as held for sale and subsequently transferred to held for investment.

[6] Effective January 1, 2017, the Bancorp has elected the fair value measurement method for all existing classes of its residential mortgage servicing rights. The servicing rights were measured at fair value at March 31, 2017 and were measu red under the amortization method at December 31, 2016.

[7] Included in other assets in the Condensed Consolidated Balance Sheets.

[8] Included in other liabilities in the Condensed Consolidat ed Balance Sheets.

[9] Includes interest-only mortgage- backed securities of $ 42 as of March 31, 2017 , recorded at fair value with fair value changes re corded in securities gains, net , in the Condensed Consolidated Statement s of Income.

[10] Includes interest-only mortgage-backed securities of $ 60 as of December 31, 2016 , recorded at fair value with fair value changes recorded in securities gains, net, in the Condensed Consolidated Statements of Income.

[11] Equity securities consist of FHLB, FRB and DTCC restricted stock holdings of $ 248 , $ 359 and $ 1 , respectively , at March 31, 2017 , that are carried at cost, and certain mutual fund and equity security holdings.

[12] Equity securities consist of FHLB, FRB and DTCC restricted stock holdings of $ 248 , $ 358 , and $ 1 , respectively, at December 31, 2016 , that are carried at cost, and certain mutual fund and equity security holdings

[13] During the three months ended March 31, 2017 , no assets or liabilities were transferred between Level 1 and Level 2.

[14] During the year ended December 31, 2016 , no assets or liabilities were transferred between Level 1 and Level 2.