Basis of Presentation - Line of Business Financial Performance (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 2,748	$ 2,714	$ 8,198	$ 8,095
Net interest income (taxable-equivalent basis), Percent change	1.30%		1.30%
Noninterest income	2,245	2,180	6,792	6,610
Noninterest income, Percent change	3.00%		2.80%
Securities gains (losses), net	(3)	(3)	2	8
Securities gains (losses), net, Percent change			(75.00%)
Total net revenue	4,990	4,891	14,992	14,713
Total net revenue, Percent change	2.00%		1.90%
Noninterest expense, Percent change	2.10%		4.60%
Other intangibles, Percent change	(7.30%)		(11.40%)
Total noninterest expense, Percent change	1.90%		4.20%
Income before provision and income taxes, Percent change	2.10%		(0.60%)
Provision for credit losses, Percent change	4.40%		(11.50%)
Income before income taxes, Percent change	1.80%		1.40%
Income taxes and taxable-equivalent adjustment, Percent change	(3.20%)		(3.60%)
Net income, Percent change	3.90%		3.40%
Net (income) loss attributable to noncontrolling interests, Percent change
Net income attributable to U.S. Bancorp, Percent change	0.20%		(0.40%)
Noninterest expense	2,563	2,510	7,763	7,425
Other intangibles	51	55	148	167
Total noninterest expense	2,614	2,565	7,911	7,592
Income before provision and income taxes	2,376	2,326	7,081	7,121
Provision for credit losses	311	298	941	1,063
Income before income taxes	2,065	2,028	6,140	6,058
Income taxes and taxable-equivalent adjustment	579	598	1,733	1,797
Net income	1,486	1,430	4,407	4,261
Net (income) loss attributable to noncontrolling interests	(15)	38	(44)	119
Net income attributable to U.S. Bancorp	1,471	1,468	4,363	4,380
Average Balance Sheet
Commercial	77,345	68,064	74,424	66,719
Commercial, Percent change	13.60%		11.50%
Commercial real estate	40,839	38,501	40,465	37,872
Commercial real estate, Percent change	6.10%		6.80%
Residential mortgages	51,994	49,139	51,799	47,055
Residential mortgages, Percent change	5.80%		10.10%
Credit card	17,753	16,931	17,516	16,627
Credit card, Percent change	4.90%		5.30%
Other retail	48,698	46,994	48,098	47,034
Other retail, Percent change	3.60%		2.30%
Total loans, excluding covered loans	236,629	219,629	232,302	215,307
Total loans, excluding covered loans, Percent change	7.70%		7.90%
Covered loans	7,238	9,733	7,796	10,375
Covered loans, Percent change	(25.60%)		(24.90%)
Total loans	243,867	229,362	240,098	225,682
Total loans, Percent change	6.30%		6.40%
Goodwill, Percent change	2.80%		1.40%
Other intangible assets, Percent change	(2.20%)		9.60%
Assets, Percent change	9.60%		6.80%
Noninterest-bearing deposits, Percent change	8.60%		7.60%
Interest checking, Percent change	12.90%		9.50%
Savings products, Percent change	14.50%		11.10%
Time deposits, Percent change	(13.10%)		(8.50%)
Total deposits, Percent change	7.40%		6.20%
Total U.S. Bancorp shareholders' equity, Percent change	8.00%		7.10%
Goodwill	9,417	9,161	9,284	9,157
Other intangible assets	3,323	3,399	3,376	3,079
Assets	385,823	352,161	375,047	351,048
Noninterest-bearing deposits	74,126	68,264	72,274	67,183
Interest checking	54,454	48,235	52,928	48,347
Savings products	100,865	88,065	96,254	86,635
Time deposits	41,563	47,804	42,206	46,119
Total deposits	271,008	252,368	263,662	248,284
Total U.S. Bancorp shareholders' equity	43,132	39,936	42,498	39,675
Wholesale Banking and Commercial Real Estate [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	518	506	1,521	1,501
Net interest income (taxable-equivalent basis), Percent change	2.40%		1.30%
Noninterest income	236	266	738	819
Noninterest income, Percent change	(11.30%)		(9.90%)
Securities gains (losses), net
Securities gains (losses), net, Percent change
Total net revenue	754	772	2,259	2,320
Total net revenue, Percent change	(2.30%)		(2.60%)
Noninterest expense, Percent change	0.70%		1.10%
Other intangibles, Percent change	(50.00%)		(50.00%)
Total noninterest expense, Percent change	0.30%		0.80%
Income before provision and income taxes, Percent change	(4.10%)		(4.90%)
Income before income taxes, Percent change	(17.50%)		(13.80%)
Income taxes and taxable-equivalent adjustment, Percent change	(17.30%)		(13.80%)
Net income, Percent change	(17.60%)		(13.80%)
Net (income) loss attributable to noncontrolling interests, Percent change
Net income attributable to U.S. Bancorp, Percent change	(17.60%)		(13.80%)
Noninterest expense	304	302	930	920
Other intangibles	1	2	3	6
Total noninterest expense	305	304	933	926
Income before provision and income taxes	449	468	1,326	1,394
Provision for credit losses	29	(41)	26	(114)
Income before income taxes	420	509	1,300	1,508
Income taxes and taxable-equivalent adjustment	153	185	473	549
Net income	267	324	827	959
Net (income) loss attributable to noncontrolling interests
Net income attributable to U.S. Bancorp	267	324	827	959
Average Balance Sheet
Commercial	59,048	51,302	57,029	50,232
Commercial, Percent change	15.10%		13.50%
Commercial real estate	21,160	19,683	20,879	19,375
Commercial real estate, Percent change	7.50%		7.80%
Residential mortgages	19	24	20	27
Residential mortgages, Percent change	(20.80%)		(25.90%)
Credit card
Credit card, Percent change
Other retail	4	6	4	7
Other retail, Percent change	(33.30%)		(42.90%)
Total loans, excluding covered loans	80,231	71,015	77,932	69,641
Total loans, excluding covered loans, Percent change	13.00%		11.90%
Covered loans	174	340	205	394
Covered loans, Percent change	(48.80%)		(48.00%)
Total loans	80,405	71,355	78,137	70,035
Total loans, Percent change	12.70%		11.60%
Goodwill, Percent change	2.70%		1.10%
Other intangible assets, Percent change	(12.50%)		(19.20%)
Assets, Percent change	12.50%		11.40%
Noninterest-bearing deposits, Percent change	6.10%		5.70%
Interest checking, Percent change	12.40%		6.40%
Savings products, Percent change	26.60%		34.60%
Time deposits, Percent change	(19.70%)		(1.30%)
Total deposits, Percent change	3.50%		9.30%
Total U.S. Bancorp shareholders' equity, Percent change	5.40%		5.30%
Goodwill	1,648	1,604	1,621	1,604
Other intangible assets	21	24	21	26
Assets	87,449	77,708	85,198	76,455
Noninterest-bearing deposits	32,684	30,812	32,029	30,299
Interest checking	11,270	10,031	11,042	10,378
Savings products	19,082	15,067	17,929	13,320
Time deposits	17,961	22,362	18,217	18,450
Total deposits	80,997	78,272	79,217	72,447
Total U.S. Bancorp shareholders' equity	7,764	7,366	7,653	7,269
Consumer and Small Business Banking [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	1,074	1,153	3,241	3,459
Net interest income (taxable-equivalent basis), Percent change	(6.90%)		(6.30%)
Noninterest income	669	717	1,967	2,268
Noninterest income, Percent change	(6.70%)		(13.30%)
Securities gains (losses), net
Securities gains (losses), net, Percent change
Total net revenue	1,743	1,870	5,208	5,727
Total net revenue, Percent change	(6.80%)		(9.10%)
Noninterest expense, Percent change	5.30%		1.30%
Other intangibles, Percent change	20.00%		(6.50%)
Total noninterest expense, Percent change	5.40%		1.20%
Income before provision and income taxes, Percent change	(25.10%)		(24.20%)
Provision for credit losses, Percent change	(51.50%)		(42.10%)
Income before income taxes, Percent change	(17.70%)		(18.30%)
Income taxes and taxable-equivalent adjustment, Percent change	(17.80%)		(18.40%)
Net income, Percent change	(17.70%)		(18.30%)
Net (income) loss attributable to noncontrolling interests, Percent change
Net income attributable to U.S. Bancorp, Percent change	(17.70%)		(18.30%)
Noninterest expense	1,169	1,110	3,421	3,377
Other intangibles	12	10	29	31
Total noninterest expense	1,181	1,120	3,450	3,408
Income before provision and income taxes	562	750	1,758	2,319
Provision for credit losses	79	163	332	573
Income before income taxes	483	587	1,426	1,746
Income taxes and taxable-equivalent adjustment	176	214	519	636
Net income	307	373	907	1,110
Net (income) loss attributable to noncontrolling interests
Net income attributable to U.S. Bancorp	307	373	907	1,110
Average Balance Sheet
Commercial	9,439	8,584	8,903	8,567
Commercial, Percent change	10.00%		3.90%
Commercial real estate	18,899	18,069	18,771	17,741
Commercial real estate, Percent change	4.60%		5.80%
Residential mortgages	50,544	48,130	50,443	46,251
Residential mortgages, Percent change	5.00%		9.10%
Credit card
Credit card, Percent change
Other retail	46,594	44,727	45,964	44,739
Other retail, Percent change	4.20%		2.70%
Total loans, excluding covered loans	125,476	119,510	124,081	117,298
Total loans, excluding covered loans, Percent change	5.00%		5.80%
Covered loans	5,688	6,434	5,871	6,690
Covered loans, Percent change	(11.60%)		(12.20%)
Total loans	131,164	125,944	129,952	123,988
Total loans, Percent change	4.10%		4.80%
Goodwill, Percent change	4.70%		1.70%
Other intangible assets, Percent change	0.50%		17.70%
Assets, Percent change	3.50%		2.30%
Noninterest-bearing deposits, Percent change	9.30%		5.70%
Interest checking, Percent change	11.70%		9.10%
Savings products, Percent change	10.10%		7.40%
Time deposits, Percent change	(14.00%)		(16.30%)
Total deposits, Percent change	6.30%		3.40%
Total U.S. Bancorp shareholders' equity, Percent change	(5.90%)		(5.30%)
Goodwill	3,680	3,515	3,577	3,516
Other intangible assets	2,664	2,650	2,698	2,293
Assets	145,604	140,621	143,337	140,056
Noninterest-bearing deposits	24,696	22,585	23,218	21,976
Interest checking	36,881	33,007	35,832	32,841
Savings products	51,229	46,532	49,496	46,106
Time deposits	17,816	20,718	18,080	21,591
Total deposits	130,622	122,842	126,626	122,514
Total U.S. Bancorp shareholders' equity	11,504	12,222	11,480	12,125
Wealth Management and Securities Services [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	96	82	270	257
Net interest income (taxable-equivalent basis), Percent change	17.10%		5.10%
Noninterest income	352	314	1,038	935
Noninterest income, Percent change	12.10%		11.00%
Securities gains (losses), net
Securities gains (losses), net, Percent change
Total net revenue	448	396	1,308	1,192
Total net revenue, Percent change	13.10%		9.70%
Noninterest expense, Percent change	3.40%		3.50%
Other intangibles, Percent change	(11.10%)		(7.40%)
Total noninterest expense, Percent change	3.00%		3.20%
Income before provision and income taxes, Percent change	66.70%		42.60%
Provision for credit losses, Percent change			14.30%
Income before income taxes, Percent change	73.70%		43.70%
Income taxes and taxable-equivalent adjustment, Percent change	71.40%		44.90%
Net income, Percent change	75.00%		43.00%
Net (income) loss attributable to noncontrolling interests, Percent change
Net income attributable to U.S. Bancorp, Percent change	75.00%		43.00%
Noninterest expense	335	324	1,002	968
Other intangibles	8	9	25	27
Total noninterest expense	343	333	1,027	995
Income before provision and income taxes	105	63	281	197
Provision for credit losses	6	6	8	7
Income before income taxes	99	57	273	190
Income taxes and taxable-equivalent adjustment	36	21	100	69
Net income	63	36	173	121
Net (income) loss attributable to noncontrolling interests
Net income attributable to U.S. Bancorp	63	36	173	121
Average Balance Sheet
Commercial	1,968	1,772	1,910	1,686
Commercial, Percent change	11.10%		13.30%
Commercial real estate	601	655	608	656
Commercial real estate, Percent change	(8.20%)		(7.30%)
Residential mortgages	1,430	984	1,335	776
Residential mortgages, Percent change	45.30%		72.00%
Credit card
Credit card, Percent change
Other retail	1,436	1,532	1,450	1,544
Other retail, Percent change	(6.30%)		(6.10%)
Total loans, excluding covered loans	5,435	4,943	5,303	4,662
Total loans, excluding covered loans, Percent change	10.00%		13.70%
Covered loans	3	17	5	14
Covered loans, Percent change	(82.40%)		(64.30%)
Total loans	5,438	4,960	5,308	4,676
Total loans, Percent change	9.60%		13.50%
Goodwill, Percent change	2.50%		2.60%
Other intangible assets, Percent change	(6.60%)		(6.30%)
Assets, Percent change	12.00%		11.90%
Noninterest-bearing deposits, Percent change	10.40%		9.50%
Interest checking, Percent change	20.80%		17.30%
Savings products, Percent change	15.40%		5.80%
Time deposits, Percent change	(5.80%)		(21.50%)
Total deposits, Percent change	12.70%		5.10%
Total U.S. Bancorp shareholders' equity, Percent change	(5.50%)		(3.90%)
Goodwill	1,572	1,533	1,568	1,529
Other intangible assets	155	166	163	174
Assets	8,679	7,751	8,409	7,514
Noninterest-bearing deposits	14,900	13,500	15,095	13,786
Interest checking	5,729	4,741	5,494	4,683
Savings products	30,373	26,326	28,650	27,070
Time deposits	3,939	4,182	4,111	5,237
Total deposits	54,941	48,749	53,350	50,776
Total U.S. Bancorp shareholders' equity	2,267	2,398	2,283	2,375
Payment Services [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	442	393	1,271	1,168
Net interest income (taxable-equivalent basis), Percent change	12.50%		8.80%
Noninterest income	842	822	2,449	2,397
Noninterest income, Percent change	2.40%		2.20%
Securities gains (losses), net
Securities gains (losses), net, Percent change
Total net revenue	1,284	1,215	3,720	3,565
Total net revenue, Percent change	5.70%		4.30%
Noninterest expense, Percent change	1.20%		2.80%
Other intangibles, Percent change	(11.80%)		(11.70%)
Total noninterest expense, Percent change	0.50%		1.90%
Income before provision and income taxes, Percent change	10.90%		6.80%
Provision for credit losses, Percent change	10.50%		3.60%
Income before income taxes, Percent change	11.10%		8.20%
Income taxes and taxable-equivalent adjustment, Percent change	10.80%		8.10%
Net income, Percent change	11.20%		8.30%
Net (income) loss attributable to noncontrolling interests, Percent change	10.00%		6.90%
Net income attributable to U.S. Bancorp, Percent change	12.00%		8.90%
Noninterest expense	582	575	1,742	1,695
Other intangibles	30	34	91	103
Total noninterest expense	612	609	1,833	1,798
Income before provision and income taxes	672	606	1,887	1,767
Provision for credit losses	190	172	573	553
Income before income taxes	482	434	1,314	1,214
Income taxes and taxable-equivalent adjustment	175	158	478	442
Net income	307	276	836	772
Net (income) loss attributable to noncontrolling interests	(9)	(10)	(27)	(29)
Net income attributable to U.S. Bancorp	298	266	809	743
Average Balance Sheet
Commercial	6,681	6,191	6,402	6,030
Commercial, Percent change	7.90%		6.20%
Commercial real estate
Commercial real estate, Percent change
Residential mortgages
Residential mortgages, Percent change
Credit card	17,753	16,931	17,516	16,627
Credit card, Percent change	4.90%		5.30%
Other retail	664	729	680	744
Other retail, Percent change	(8.90%)		(8.60%)
Total loans, excluding covered loans	25,098	23,851	24,598	23,401
Total loans, excluding covered loans, Percent change	5.20%		5.10%
Covered loans	5	5	5	5
Covered loans, Percent change
Total loans	25,103	23,856	24,603	23,406
Total loans, Percent change	5.20%		5.10%
Goodwill, Percent change	0.30%		0.40%
Other intangible assets, Percent change	(13.30%)		(15.40%)
Assets, Percent change	4.30%		4.20%
Noninterest-bearing deposits, Percent change	(1.70%)		1.40%
Interest checking, Percent change	25.90%		25.90%
Savings products, Percent change	35.00%		40.70%
Time deposits, Percent change
Total deposits, Percent change	10.30%		12.30%
Total U.S. Bancorp shareholders' equity, Percent change	(6.80%)		(5.90%)
Goodwill	2,517	2,509	2,518	2,508
Other intangible assets	483	557	494	584
Assets	31,407	30,123	30,901	29,659
Noninterest-bearing deposits	702	714	704	694
Interest checking	573	455	559	444
Savings products	81	60	76	54
Time deposits
Total deposits	1,356	1,229	1,339	1,192
Total U.S. Bancorp shareholders' equity	5,690	6,102	5,675	6,033
Treasury and Corporate Support [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	618	580	1,895	1,710
Net interest income (taxable-equivalent basis), Percent change	6.60%		10.80%
Noninterest income	146	61	600	191
Securities gains (losses), net	(3)	(3)	2	8
Securities gains (losses), net, Percent change			(75.00%)
Total net revenue	761	638	2,497	1,909
Total net revenue, Percent change	19.30%		30.80%
Noninterest expense, Percent change	(13.10%)		43.70%
Other intangibles, Percent change
Total noninterest expense, Percent change	(13.10%)		43.70%
Income before provision and income taxes, Percent change	33.90%		26.70%
Provision for credit losses, Percent change			(95.50%)
Income before income taxes, Percent change	31.70%		30.50%
Income taxes and taxable-equivalent adjustment, Percent change	95.00%		61.40%
Net income, Percent change	28.70%		28.10%
Net (income) loss attributable to noncontrolling interests, Percent change
Net income attributable to U.S. Bancorp, Percent change	14.30%		13.80%
Noninterest expense	173	199	668	465
Other intangibles
Total noninterest expense	173	199	668	465
Income before provision and income taxes	588	439	1,829	1,444
Provision for credit losses	7	(2)	2	44
Income before income taxes	581	441	1,827	1,400
Income taxes and taxable-equivalent adjustment	39	20	163	101
Net income	542	421	1,664	1,299
Net (income) loss attributable to noncontrolling interests	(6)	48	(17)	148
Net income attributable to U.S. Bancorp	536	469	1,647	1,447
Average Balance Sheet
Commercial	209	215	180	204
Commercial, Percent change	(2.80%)		(11.80%)
Commercial real estate	179	94	207	100
Commercial real estate, Percent change	90.40%
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	389	310	388	305
Total loans, excluding covered loans, Percent change	25.50%		27.20%
Covered loans	1,368	2,937	1,710	3,272
Covered loans, Percent change	(53.40%)		(47.70%)
Total loans	1,757	3,247	2,098	3,577
Total loans, Percent change	(45.90%)		(41.30%)
Goodwill, Percent change
Assets, Percent change	17.40%		10.10%
Noninterest-bearing deposits, Percent change	75.20%
Interest checking, Percent change
Savings products, Percent change	25.00%		21.20%
Total U.S. Bancorp shareholders' equity, Percent change	34.30%		29.80%
Goodwill
Other intangible assets		2		2
Assets	112,684	95,958	107,202	97,364
Noninterest-bearing deposits	1,144	653	1,228	428
Interest checking	1	1	1	1
Savings products	100	80	103	85
Time deposits	1,847	542	1,798	841
Total deposits	3,092	1,276	3,130	1,355
Total U.S. Bancorp shareholders' equity	$ 15,907	$ 11,848	$ 15,407	$ 11,873