Basis of Presentation - Line of Business Financial Performance (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 2,744	$ 2,672	$ 5,450	$ 5,381
Net interest income (taxable-equivalent basis), Percent change	2.70%		1.30%
Noninterest income	2,444	2,270	4,547	4,430
Noninterest income, Percent change	7.70%		2.60%
Securities gains (losses), net		6	5	11
Securities gains (losses), net, Percent change			(54.50%)
Total net revenue	5,188	4,948	10,002	9,822
Total net revenue, Percent change	4.90%		1.80%
Noninterest expense, Percent change	8.10%		5.80%
Other intangibles, Percent change	(12.70%)		(13.40%)
Total noninterest expense, Percent change	7.70%		5.40%
Income before provision and income taxes, Percent change	1.80%		(1.90%)
Provision for credit losses, Percent change	(10.50%)		(17.60%)
Income before income taxes, Percent change	4.00%		1.10%
Income taxes and taxable-equivalent adjustment, Percent change	2.90%		(3.80%)
Net income, Percent change	4.50%		3.20%
Net (income) loss attributable to noncontrolling interests, Percent change
Net income attributable to U.S. Bancorp, Percent change	0.70%		(0.70%)
Noninterest expense	2,705	2,502	5,200	4,915
Other intangibles	48	55	97	112
Total noninterest expense	2,753	2,557	5,297	5,027
Income before provision and income taxes	2,435	2,391	4,705	4,795
Provision for credit losses	324	362	630	765
Income before income taxes	2,111	2,029	4,075	4,030
Income taxes and taxable-equivalent adjustment	602	585	1,154	1,199
Net income	1,509	1,444	2,921	2,831
Net (income) loss attributable to noncontrolling interests	(14)	40	(29)	81
Net income attributable to U.S. Bancorp	1,495	1,484	2,892	2,912
Average Balance Sheet
Commercial	75,020	66,762	72,939	66,034
Commercial, Percent change	12.40%		10.50%
Commercial real estate	40,497	37,884	40,275	37,553
Commercial real estate, Percent change	6.90%		7.20%
Residential mortgages	51,815	46,873	51,700	45,996
Residential mortgages, Percent change	10.50%		12.40%
Credit card	17,384	16,416	17,395	16,472
Credit card, Percent change	5.90%		5.60%
Other retail	47,928	46,866	47,793	47,055
Other retail, Percent change	2.30%		1.60%
Total loans, excluding covered loans	232,644	214,801	230,102	213,110
Total loans, excluding covered loans, Percent change	8.30%		8.00%
Covered loans	7,836	10,385	8,080	10,701
Covered loans, Percent change	(24.50%)		(24.50%)
Total loans	240,480	225,186	238,182	223,811
Total loans, Percent change	6.80%		6.40%
Goodwill, Percent change	0.80%		0.70%
Other intangible assets, Percent change	12.40%		16.70%
Assets, Percent change	7.20%		5.40%
Noninterest-bearing deposits, Percent change	7.40%		7.10%
Interest checking, Percent change	9.50%		7.70%
Savings products, Percent change	9.20%		9.30%
Time deposits, Percent change	(5.90%)		(6.00%)
Total deposits, Percent change	6.00%		5.60%
Total U.S. Bancorp shareholders' equity, Percent change	6.70%		6.70%
Goodwill	9,228	9,154	9,216	9,154
Other intangible assets	3,365	2,994	3,403	2,917
Assets	374,769	349,589	369,569	350,483
Noninterest-bearing deposits	71,837	66,866	71,333	66,634
Interest checking	52,989	48,403	52,152	48,404
Savings products	95,361	87,297	93,910	85,908
Time deposits	42,164	44,819	42,533	45,262
Total deposits	262,351	247,385	259,928	246,208
Total U.S. Bancorp shareholders' equity	42,586	39,904	42,176	39,543
Wholesale Banking and Commercial Real Estate [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	513	501	1,003	995
Net interest income (taxable-equivalent basis), Percent change	2.40%		0.80%
Noninterest income	260	275	505	555
Noninterest income, Percent change	(5.50%)		(9.00%)
Securities gains (losses), net
Securities gains (losses), net, Percent change
Total net revenue	773	776	1,508	1,550
Total net revenue, Percent change	(0.40%)		(2.70%)
Noninterest expense, Percent change	1.90%		1.30%
Other intangibles, Percent change	(50.00%)		(50.00%)
Total noninterest expense, Percent change	1.60%		1.00%
Income before provision and income taxes, Percent change	(1.70%)		(5.20%)
Provision for credit losses, Percent change			95.90%
Income before income taxes, Percent change	(12.00%)		(11.80%)
Income taxes and taxable-equivalent adjustment, Percent change	(12.10%)		(11.80%)
Net income, Percent change	(11.90%)		(11.80%)
Net (income) loss attributable to noncontrolling interests, Percent change
Net income attributable to U.S. Bancorp, Percent change	(11.90%)		(11.80%)
Noninterest expense	316	310	626	618
Other intangibles	1	2	2	4
Total noninterest expense	317	312	628	622
Income before provision and income taxes	456	464	880	928
Provision for credit losses	15	(37)	(3)	(73)
Income before income taxes	441	501	883	1,001
Income taxes and taxable-equivalent adjustment	160	182	321	364
Net income	281	319	562	637
Net (income) loss attributable to noncontrolling interests
Net income attributable to U.S. Bancorp	281	319	562	637
Average Balance Sheet
Commercial	57,472	50,238	55,989	49,688
Commercial, Percent change	14.40%		12.70%
Commercial real estate	20,884	19,435	20,729	19,216
Commercial real estate, Percent change	7.50%		7.90%
Residential mortgages	20	28	21	28
Residential mortgages, Percent change	(28.60%)		(25.00%)
Credit card
Credit card, Percent change
Other retail	4	7	4	8
Other retail, Percent change	(42.90%)		(50.00%)
Total loans, excluding covered loans	78,380	69,708	76,743	68,940
Total loans, excluding covered loans, Percent change	12.40%		11.30%
Covered loans	196	377	220	422
Covered loans, Percent change	(48.00%)		(47.90%)
Total loans	78,576	70,085	76,963	69,362
Total loans, Percent change	12.10%		11.00%
Goodwill, Percent change
Other intangible assets, Percent change	(19.20%)		(22.20%)
Assets, Percent change	11.60%		10.80%
Noninterest-bearing deposits, Percent change	3.50%		5.60%
Interest checking, Percent change	11.20%		3.50%
Savings products, Percent change	35.60%		39.60%
Time deposits, Percent change	11.30%		11.50%
Total deposits, Percent change	12.40%		12.80%
Total U.S. Bancorp shareholders' equity, Percent change	5.00%		5.20%
Goodwill	1,604	1,604	1,604	1,604
Other intangible assets	21	26	21	27
Assets	85,794	76,900	84,029	75,816
Noninterest-bearing deposits	31,258	30,199	31,737	30,057
Interest checking	11,379	10,233	10,925	10,555
Savings products	17,607	12,986	17,373	12,445
Time deposits	18,309	16,448	18,347	16,461
Total deposits	78,553	69,866	78,382	69,518
Total U.S. Bancorp shareholders' equity	7,656	7,288	7,591	7,219
Consumer and Small Business Banking [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	1,077	1,143	2,167	2,306
Net interest income (taxable-equivalent basis), Percent change	(5.80%)		(6.00%)
Noninterest income	678	771	1,295	1,549
Noninterest income, Percent change	(12.10%)		(16.40%)
Securities gains (losses), net
Securities gains (losses), net, Percent change
Total net revenue	1,755	1,914	3,462	3,855
Total net revenue, Percent change	(8.30%)		(10.20%)
Noninterest expense, Percent change	1.00%		(0.40%)
Other intangibles, Percent change	(20.00%)		(23.80%)
Total noninterest expense, Percent change	0.80%		(0.70%)
Income before provision and income taxes, Percent change	(21.50%)		(24.20%)
Provision for credit losses, Percent change	(34.10%)		(38.30%)
Income before income taxes, Percent change	(17.70%)		(19.10%)
Income taxes and taxable-equivalent adjustment, Percent change	(17.90%)		(19.30%)
Net income, Percent change	(17.60%)		(19.00%)
Net (income) loss attributable to noncontrolling interests, Percent change
Net income attributable to U.S. Bancorp, Percent change	(17.60%)		(19.00%)
Noninterest expense	1,134	1,123	2,259	2,269
Other intangibles	8	10	16	21
Total noninterest expense	1,142	1,133	2,275	2,290
Income before provision and income taxes	613	781	1,187	1,565
Provision for credit losses	120	182	253	410
Income before income taxes	493	599	934	1,155
Income taxes and taxable-equivalent adjustment	179	218	339	420
Net income	314	381	595	735
Net (income) loss attributable to noncontrolling interests
Net income attributable to U.S. Bancorp	314	381	595	735
Average Balance Sheet
Commercial	8,947	8,616	8,642	8,558
Commercial, Percent change	3.80%		1.00%
Commercial real estate	18,800	17,690	18,712	17,577
Commercial real estate, Percent change	6.30%		6.50%
Residential mortgages	50,485	46,085	50,391	45,297
Residential mortgages, Percent change	9.50%		11.20%
Credit card
Credit card, Percent change
Other retail	45,804	44,570	45,644	44,744
Other retail, Percent change	2.80%		2.00%
Total loans, excluding covered loans	124,036	116,961	123,389	116,176
Total loans, excluding covered loans, Percent change	6.00%		6.20%
Covered loans	5,882	6,713	5,965	6,820
Covered loans, Percent change	(12.40%)		(12.50%)
Total loans	129,918	123,674	129,354	122,996
Total loans, Percent change	5.00%		5.20%
Goodwill, Percent change	0.70%		0.30%
Other intangible assets, Percent change	21.80%		28.50%
Assets, Percent change	2.40%		1.70%
Noninterest-bearing deposits, Percent change	4.60%		3.70%
Interest checking, Percent change	8.00%		7.80%
Savings products, Percent change	6.40%		5.90%
Time deposits, Percent change	(18.10%)		(17.30%)
Total deposits, Percent change	2.20%		1.80%
Total U.S. Bancorp shareholders' equity, Percent change	(6.00%)		(5.00%)
Goodwill	3,539	3,515	3,527	3,515
Other intangible assets	2,690	2,208	2,715	2,113
Assets	142,708	139,313	142,203	139,769
Noninterest-bearing deposits	22,900	21,886	22,425	21,623
Interest checking	35,683	33,041	35,270	32,716
Savings products	49,103	46,145	48,578	45,859
Time deposits	17,720	21,626	18,211	22,033
Total deposits	125,406	122,698	124,484	122,231
Total U.S. Bancorp shareholders' equity	11,380	12,112	11,474	12,076
Wealth Management and Securities Services [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	91	87	174	175
Net interest income (taxable-equivalent basis), Percent change	4.60%		(0.60%)
Noninterest income	347	318	686	621
Noninterest income, Percent change	9.10%		10.50%
Securities gains (losses), net
Securities gains (losses), net, Percent change
Total net revenue	438	405	860	796
Total net revenue, Percent change	8.10%		8.00%
Noninterest expense, Percent change	4.70%		4.00%
Other intangibles, Percent change
Total noninterest expense, Percent change	4.60%		3.90%
Income before provision and income taxes, Percent change	23.70%		28.40%
Provision for credit losses, Percent change
Income before income taxes, Percent change	17.30%		27.80%
Income taxes and taxable-equivalent adjustment, Percent change	18.50%		29.20%
Net income, Percent change	16.70%		27.10%
Net (income) loss attributable to noncontrolling interests, Percent change
Net income attributable to U.S. Bancorp, Percent change	16.70%		27.10%
Noninterest expense	335	320	670	644
Other intangibles	9	9	18	18
Total noninterest expense	344	329	688	662
Income before provision and income taxes	94	76	172	134
Provision for credit losses	6	1	2	1
Income before income taxes	88	75	170	133
Income taxes and taxable-equivalent adjustment	32	27	62	48
Net income	56	48	108	85
Net (income) loss attributable to noncontrolling interests
Net income attributable to U.S. Bancorp	56	48	108	85
Average Balance Sheet
Commercial	1,918	1,667	1,881	1,642
Commercial, Percent change	15.10%		14.60%
Commercial real estate	608	658	613	657
Commercial real estate, Percent change	(7.60%)		(6.70%)
Residential mortgages	1,309	759	1,287	670
Residential mortgages, Percent change	72.50%		92.10%
Credit card
Credit card, Percent change
Other retail	1,442	1,548	1,457	1,551
Other retail, Percent change	(6.80%)		(6.10%)
Total loans, excluding covered loans	5,277	4,632	5,238	4,520
Total loans, excluding covered loans, Percent change	13.90%		15.90%
Covered loans	6	15	6	12
Covered loans, Percent change	(60.00%)		(50.00%)
Total loans	5,283	4,647	5,244	4,532
Total loans, Percent change	13.70%		15.70%
Goodwill, Percent change	2.50%		2.60%
Other intangible assets, Percent change	(5.20%)		(5.60%)
Assets, Percent change	11.00%		11.90%
Noninterest-bearing deposits, Percent change	13.50%		8.90%
Interest checking, Percent change	14.60%		15.20%
Savings products, Percent change	1.60%		1.20%
Time deposits, Percent change	(24.20%)		(27.20%)
Total deposits, Percent change	3.10%		1.30%
Total U.S. Bancorp shareholders' equity, Percent change	(3.50%)		(3.10%)
Goodwill	1,565	1,527	1,566	1,527
Other intangible assets	164	173	167	177
Assets	8,327	7,501	8,274	7,394
Noninterest-bearing deposits	15,674	13,812	15,196	13,957
Interest checking	5,363	4,680	5,405	4,693
Savings products	28,469	28,031	27,782	27,466
Time deposits	4,238	5,592	4,202	5,775
Total deposits	53,744	52,115	52,585	51,891
Total U.S. Bancorp shareholders' equity	2,285	2,368	2,290	2,364
Payment Services [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	415	387	829	775
Net interest income (taxable-equivalent basis), Percent change	7.20%		7.00%
Noninterest income	832	828	1,607	1,575
Noninterest income, Percent change	0.50%		2.00%
Securities gains (losses), net
Securities gains (losses), net, Percent change
Total net revenue	1,247	1,215	2,436	2,350
Total net revenue, Percent change	2.60%		3.70%
Noninterest expense, Percent change	1.40%		2.50%
Other intangibles, Percent change	(11.80%)		(11.60%)
Total noninterest expense, Percent change	0.70%		1.70%
Income before provision and income taxes, Percent change	4.60%		5.70%
Provision for credit losses, Percent change	3.40%		0.50%
Income before income taxes, Percent change	5.00%		8.20%
Income taxes and taxable-equivalent adjustment, Percent change	5.00%		8.10%
Net income, Percent change	5.00%		8.20%
Net (income) loss attributable to noncontrolling interests, Percent change	10.00%		5.30%
Net income attributable to U.S. Bancorp, Percent change	5.60%		8.80%
Noninterest expense	574	566	1,145	1,117
Other intangibles	30	34	61	69
Total noninterest expense	604	600	1,206	1,186
Income before provision and income taxes	643	615	1,230	1,164
Provision for credit losses	182	176	383	381
Income before income taxes	461	439	847	783
Income taxes and taxable-equivalent adjustment	168	160	308	285
Net income	293	279	539	498
Net (income) loss attributable to noncontrolling interests	(9)	(10)	(18)	(19)
Net income attributable to U.S. Bancorp	284	269	521	479
Average Balance Sheet
Commercial	6,522	6,035	6,261	5,948
Commercial, Percent change	8.10%		5.30%
Commercial real estate
Commercial real estate, Percent change
Residential mortgages
Residential mortgages, Percent change
Credit card	17,384	16,416	17,395	16,472
Credit card, Percent change	5.90%		5.60%
Other retail	678	741	688	752
Other retail, Percent change	(8.50%)		(8.50%)
Total loans, excluding covered loans	24,584	23,192	24,344	23,172
Total loans, excluding covered loans, Percent change	6.00%		5.10%
Covered loans	5	5	5	5
Covered loans, Percent change
Total loans	24,589	23,197	24,349	23,177
Total loans, Percent change	6.00%		5.10%
Goodwill, Percent change	0.50%		0.40%
Other intangible assets, Percent change	(16.20%)		(16.60%)
Assets, Percent change	5.10%		4.10%
Noninterest-bearing deposits, Percent change	5.30%		3.10%
Interest checking, Percent change	25.70%		25.50%
Savings products, Percent change	40.70%		46.00%
Time deposits, Percent change
Total deposits, Percent change	14.70%		13.30%
Total U.S. Bancorp shareholders' equity, Percent change	(6.10%)		(5.60%)
Goodwill	2,520	2,508	2,519	2,508
Other intangible assets	490	585	499	598
Assets	30,913	29,402	30,643	29,422
Noninterest-bearing deposits	711	675	704	683
Interest checking	563	448	551	439
Savings products	76	54	73	50
Time deposits
Total deposits	1,350	1,177	1,328	1,172
Total U.S. Bancorp shareholders' equity	5,664	6,033	5,660	5,997
Treasury and Corporate Support [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	648	554	1,277	1,130
Net interest income (taxable-equivalent basis), Percent change	17.00%		13.00%
Noninterest income	327	78	454	130
Noninterest income, Percent change
Securities gains (losses), net		6	5	11
Securities gains (losses), net, Percent change			(54.50%)
Total net revenue	975	638	1,736	1,271
Total net revenue, Percent change	52.80%		36.60%
Noninterest expense, Percent change	89.10%		87.30%
Other intangibles, Percent change
Total noninterest expense, Percent change	89.10%		87.30%
Income before provision and income taxes, Percent change	38.20%		23.10%
Provision for credit losses, Percent change	(97.50%)
Income before income taxes, Percent change	51.30%		29.50%
Income taxes and taxable-equivalent adjustment, Percent change			51.20%
Net income, Percent change	35.50%		27.50%
Net (income) loss attributable to noncontrolling interests, Percent change
Net income attributable to U.S. Bancorp, Percent change	19.90%		13.30%
Noninterest expense	346	183	500	267
Other intangibles
Total noninterest expense	346	183	500	267
Income before provision and income taxes	629	455	1,236	1,004
Provision for credit losses	1	40	(5)	46
Income before income taxes	628	415	1,241	958
Income taxes and taxable-equivalent adjustment	63	(2)	124	82
Net income	565	417	1,117	876
Net (income) loss attributable to noncontrolling interests	(5)	50	(11)	100
Net income attributable to U.S. Bancorp	560	467	1,106	976
Average Balance Sheet
Commercial	161	206	166	198
Commercial, Percent change	(21.80%)		(16.20%)
Commercial real estate	205	101	221	103
Commercial real estate, Percent change
Residential mortgages	1	1	1	1
Residential mortgages, Percent change
Credit card
Credit card, Percent change
Other retail
Other retail, Percent change
Total loans, excluding covered loans	367	308	388	302
Total loans, excluding covered loans, Percent change	19.20%		28.50%
Covered loans	1,747	3,275	1,884	3,442
Covered loans, Percent change	(46.70%)		(45.30%)
Total loans	2,114	3,583	2,272	3,744
Total loans, Percent change	(41.00%)		(39.30%)
Goodwill, Percent change
Other intangible assets, Percent change			(50.00%)
Assets, Percent change	10.90%		6.50%
Noninterest-bearing deposits, Percent change
Interest checking, Percent change
Savings products, Percent change	30.90%		18.20%
Time deposits, Percent change	64.50%		78.50%
Total deposits, Percent change
Total U.S. Bancorp shareholders' equity, Percent change	28.90%		27.50%
Goodwill
Other intangible assets		2	1	2
Assets	107,027	96,473	104,420	98,082
Noninterest-bearing deposits	1,294	294	1,271	314
Interest checking	1	1	1	1
Savings products	106	81	104	88
Time deposits	1,897	1,153	1,773	993
Total deposits	3,298	1,529	3,149	1,396
Total U.S. Bancorp shareholders' equity	$ 15,601	$ 12,103	$ 15,161	$ 11,887