Basis of Presentation - Line of Business Financial Performance (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 3,068	$ 2,896	$ 6,063	$ 5,784
Net interest income (taxable-equivalent basis), Percent change	5.90%		4.80%
Noninterest income	$ 2,410	2,549	$ 4,710	4,695
Noninterest income, Percent change	(5.50%)		0.30%
Securities gains (losses), net	$ 9	3	$ 38	6
Securities gains (losses), net, Percent change	0.00%		0.00%
Total net revenue	$ 5,487	5,448	$ 10,811	10,485
Total net revenue, Percent change	0.70%		3.10%
Noninterest expense, Percent change	1.10%		4.00%
Other intangibles, Percent change	(2.30%)		(2.20%)
Total noninterest expense, Percent change	1.00%		3.90%
Income before provision and income taxes, Percent change	0.30%		2.10%
Provision for credit losses, Percent change	7.00%		5.80%
Income before income taxes, Percent change	(0.70%)		1.50%
Income taxes and taxable-equivalent adjustment, Percent change	1.50%		0.10%
Net income, Percent change	(1.60%)		2.10%
Net (income) loss attributable to noncontrolling interests, Percent change	14.30%		13.80%
Net income attributable to U.S. Bancorp, Percent change	(1.40%)		2.20%
Noninterest expense	$ 2,980	2,948	$ 5,880	5,652
Other intangibles	43	44	87	89
Total noninterest expense	3,023	2,992	5,967	5,741
Income before provision and income taxes	2,464	2,456	4,844	4,744
Provision for credit losses	350	327	695	657
Income before income taxes	2,114	2,129	4,149	4,087
Income taxes and taxable-equivalent adjustment	602	593	1,151	1,150
Net income	1,512	1,536	2,998	2,937
Net (income) loss attributable to noncontrolling interests	(12)	(14)	(25)	(29)
Net income attributable to U.S. Bancorp	1,500	1,522	2,973	2,908
Average Balance Sheet
Commercial	$ 95,638	92,154	$ 94,694	90,987
Commercial, Percent change	3.80%		4.10%
Commercial real estate	$ 42,549	42,988	$ 42,852	42,694
Commercial real estate, Percent change	(1.00%)		0.40%
Residential mortgages	$ 58,544	55,501	$ 58,224	54,854
Residential mortgages, Percent change	5.50%		6.10%
Credit card	$ 20,631	20,140	$ 20,737	20,192
Credit card, Percent change	2.40%		2.70%
Other retail	$ 54,627	51,468	$ 54,208	51,283
Other retail, Percent change	6.10%		5.70%
Total loans, excluding covered loans	$ 271,989	262,251	$ 270,715	260,010
Total loans, excluding covered loans, Percent change	3.70%		4.10%
Covered loans	$ 3,539	4,331	$ 3,635	4,422
Covered loans, Percent change	(18.30%)		(17.80%)
Total loans	$ 275,528	266,582	$ 274,350	264,432
Total loans, Percent change	3.40%		3.80%
Goodwill, Percent change	(0.20%)		(0.10%)
Other intangible assets, Percent change	6.90%		5.90%
Assets, Percent change	4.00%		4.40%
Noninterest-bearing deposits, Percent change	4.50%		3.60%
Interest checking, Percent change	10.60%		12.00%
Savings products, Percent change	12.90%		16.50%
Time deposits, Percent change	(9.80%)		(9.40%)
Total deposits, Percent change	7.70%		9.30%
Total U.S. Bancorp shareholders' equity, Percent change	2.30%		2.40%
Goodwill	$ 9,353	9,368	$ 9,350	9,363
Other intangible assets	3,235	3,026	3,270	3,087
Assets	446,105	428,750	443,721	425,153
Noninterest-bearing deposits	82,710	79,171	81,729	78,870
Interest checking	67,290	60,842	66,490	59,376
Savings products	150,301	133,162	150,832	129,437
Time deposits	30,871	34,211	30,759	33,949
Total deposits	331,172	307,386	329,810	301,632
Total U.S. Bancorp shareholders' equity	48,273	47,184	48,099	46,961
Wholesale Banking and Commercial Real Estate [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 602	546	$ 1,190	1,075
Net interest income (taxable-equivalent basis), Percent change	10.30%		10.70%
Noninterest income	$ 238	250	$ 482	456
Noninterest income, Percent change	(4.80%)		5.70%
Securities gains (losses), net			$ (3)
Securities gains (losses), net, Percent change	0.00%		0.00%
Total net revenue	$ 840	796	$ 1,669	1,531
Total net revenue, Percent change	5.50%		9.00%
Noninterest expense, Percent change	9.90%		10.60%
Total noninterest expense, Percent change	9.90%		10.60%
Income before provision and income taxes, Percent change	1.90%		7.60%
Provision for credit losses, Percent change			(93.30%)
Income before income taxes, Percent change	25.80%		57.30%
Income taxes and taxable-equivalent adjustment, Percent change	26.50%		58.10%
Net income, Percent change	25.40%		56.90%
Net income attributable to U.S. Bancorp, Percent change	25.40%		56.90%
Noninterest expense	$ 399	363	$ 790	714
Other intangibles	1	1	2	2
Total noninterest expense	400	364	792	716
Income before provision and income taxes	440	432	877	815
Provision for credit losses	(18)	68	18	269
Income before income taxes	458	364	859	546
Income taxes and taxable-equivalent adjustment	167	132	313	198
Net income	291	232	546	348
Net income attributable to U.S. Bancorp	291	232	546	348
Average Balance Sheet
Commercial	$ 73,394	70,929	$ 72,906	70,212
Commercial, Percent change	3.50%		3.80%
Commercial real estate	$ 20,820	21,153	$ 21,062	20,897
Commercial real estate, Percent change	(1.60%)		0.80%
Residential mortgages	$ 6	7	$ 7	7
Residential mortgages, Percent change	(14.30%)
Other retail	$ 1	2	$ 1	2
Other retail, Percent change	(50.00%)		(50.00%)
Total loans, excluding covered loans	$ 94,221	92,091	$ 93,976	91,118
Total loans, excluding covered loans, Percent change	2.30%		3.10%
Total loans	$ 94,221	92,091	$ 93,976	91,118
Total loans, Percent change	2.30%		3.10%
Other intangible assets, Percent change	(17.60%)		(22.20%)
Assets, Percent change	2.60%		3.30%
Noninterest-bearing deposits, Percent change	0.50%		0.50%
Interest checking, Percent change	17.80%		25.70%
Savings products, Percent change	14.60%		24.80%
Time deposits, Percent change	1.20%		2.10%
Total deposits, Percent change	7.80%		12.40%
Total U.S. Bancorp shareholders' equity, Percent change	10.70%		10.20%
Goodwill	$ 1,647	1,647	$ 1,647	1,647
Other intangible assets	14	17	14	18
Assets	103,099	100,475	102,706	99,459
Noninterest-bearing deposits	36,362	36,183	36,622	36,441
Interest checking	9,547	8,101	9,402	7,481
Savings products	45,763	39,933	47,274	37,879
Time deposits	13,549	13,384	13,015	12,752
Total deposits	105,221	97,601	106,313	94,553
Total U.S. Bancorp shareholders' equity	9,921	8,966	9,801	8,892
Consumer and Small Business Banking [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 1,258	1,167	$ 2,480	2,324
Net interest income (taxable-equivalent basis), Percent change	7.80%		6.70%
Noninterest income	$ 620	636	$ 1,205	1,187
Noninterest income, Percent change	(2.50%)		1.50%
Securities gains (losses), net, Percent change	0.00%		0.00%
Total net revenue	$ 1,878	1,803	$ 3,685	3,511
Total net revenue, Percent change	4.20%		5.00%
Noninterest expense, Percent change	4.00%		4.10%
Other intangibles, Percent change	(12.50%)		(12.50%)
Total noninterest expense, Percent change	3.90%		4.00%
Income before provision and income taxes, Percent change	4.80%		7.10%
Income before income taxes, Percent change	(3.70%)		(9.60%)
Income taxes and taxable-equivalent adjustment, Percent change	(3.70%)		(9.70%)
Net income, Percent change	(3.60%)		(9.50%)
Net income attributable to U.S. Bancorp, Percent change	(3.60%)		(9.50%)
Noninterest expense	$ 1,280	1,231	$ 2,541	2,440
Other intangibles	7	8	14	16
Total noninterest expense	1,287	1,239	2,555	2,456
Income before provision and income taxes	591	564	1,130	1,055
Provision for credit losses	90	44	155	(23)
Income before income taxes	501	520	975	1,078
Income taxes and taxable-equivalent adjustment	182	189	354	392
Net income	319	331	621	686
Net income attributable to U.S. Bancorp	319	331	621	686
Average Balance Sheet
Commercial	$ 10,235	10,504	$ 10,076	10,276
Commercial, Percent change	(2.60%)		(1.90%)
Commercial real estate	$ 18,503	18,119	$ 18,527	18,070
Commercial real estate, Percent change	2.10%		2.50%
Residential mortgages	$ 55,787	53,316	$ 55,519	52,720
Residential mortgages, Percent change	4.60%		5.30%
Other retail	$ 52,486	49,413	$ 52,089	49,208
Other retail, Percent change	6.20%		5.90%
Total loans, excluding covered loans	$ 137,011	131,352	$ 136,211	130,274
Total loans, excluding covered loans, Percent change	4.30%		4.60%
Covered loans	$ 3,532	4,296	$ 3,624	4,381
Covered loans, Percent change	(17.80%)		(17.30%)
Total loans	$ 140,543	135,648	$ 139,835	134,655
Total loans, Percent change	3.60%		3.80%
Other intangible assets, Percent change	13.80%		11.90%
Assets, Percent change	2.40%		3.10%
Noninterest-bearing deposits, Percent change	1.30%		2.60%
Interest checking, Percent change	8.80%		9.30%
Savings products, Percent change	6.00%		6.40%
Time deposits, Percent change	(10.10%)		(9.90%)
Total deposits, Percent change	4.40%		4.90%
Total U.S. Bancorp shareholders' equity, Percent change	3.20%		3.90%
Goodwill	$ 3,681	3,681	$ 3,681	3,681
Other intangible assets	2,730	2,399	2,749	2,456
Assets	154,245	150,588	153,954	149,299
Noninterest-bearing deposits	27,304	26,951	27,136	26,457
Interest checking	47,372	43,549	46,846	42,841
Savings products	60,696	57,238	60,298	56,678
Time deposits	12,810	14,249	13,011	14,448
Total deposits	148,182	141,987	147,291	140,424
Total U.S. Bancorp shareholders' equity	11,436	11,082	11,479	11,051
Wealth Management and Securities Services [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 187	122	$ 366	239
Net interest income (taxable-equivalent basis), Percent change	53.30%		53.10%
Noninterest income	$ 413	401	$ 811	780
Noninterest income, Percent change	3.00%		4.00%
Securities gains (losses), net, Percent change	0.00%		0.00%
Total net revenue	$ 600	523	$ 1,177	1,019
Total net revenue, Percent change	14.70%		15.50%
Noninterest expense, Percent change	9.60%		8.60%
Other intangibles, Percent change	(16.70%)		(16.70%)
Total noninterest expense, Percent change	9.10%		8.20%
Income before provision and income taxes, Percent change	28.50%		36.00%
Income before income taxes, Percent change	30.00%		35.40%
Income taxes and taxable-equivalent adjustment, Percent change	29.10%		34.70%
Net income, Percent change	30.50%		35.90%
Net income attributable to U.S. Bancorp, Percent change	30.50%		35.90%
Noninterest expense	$ 401	366	$ 804	740
Other intangibles	5	6	10	12
Total noninterest expense	406	372	814	752
Income before provision and income taxes	194	151	363	267
Provision for credit losses	(1)	1		(1)
Income before income taxes	195	150	363	268
Income taxes and taxable-equivalent adjustment	71	55	132	98
Net income	124	95	231	170
Net income attributable to U.S. Bancorp	124	95	231	170
Average Balance Sheet
Commercial	$ 3,374	2,835	$ 3,282	2,865
Commercial, Percent change	19.00%		14.60%
Commercial real estate	$ 507	521	$ 510	530
Commercial real estate, Percent change	(2.70%)		(3.80%)
Residential mortgages	$ 2,751	2,178	$ 2,698	2,127
Residential mortgages, Percent change	26.30%		26.80%
Other retail	$ 1,676	1,522	$ 1,646	1,532
Other retail, Percent change	10.10%		7.40%
Total loans, excluding covered loans	$ 8,308	7,056	$ 8,136	7,054
Total loans, excluding covered loans, Percent change	17.70%		15.30%
Total loans	$ 8,308	7,056	$ 8,136	7,054
Total loans, Percent change	17.70%		15.30%
Goodwill, Percent change	(0.10%)		(0.10%)
Other intangible assets, Percent change	(20.20%)		(20.60%)
Assets, Percent change	13.40%		12.20%
Noninterest-bearing deposits, Percent change	22.00%		14.90%
Interest checking, Percent change	12.80%		13.20%
Savings products, Percent change	22.30%		24.60%
Time deposits, Percent change	9.70%		21.30%
Total deposits, Percent change	20.00%		20.60%
Total U.S. Bancorp shareholders' equity, Percent change	(0.80%)		0.10%
Goodwill	$ 1,567	1,568	$ 1,567	1,568
Other intangible assets	83	104	85	107
Assets	11,427	10,081	11,435	10,188
Noninterest-bearing deposits	15,971	13,096	14,925	12,995
Interest checking	10,321	9,148	10,197	9,010
Savings products	43,300	35,393	42,713	34,287
Time deposits	4,286	3,908	4,520	3,727
Total deposits	73,878	61,545	72,355	60,019
Total U.S. Bancorp shareholders' equity	2,365	2,385	2,383	2,380
Payment Services [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 540	513	$ 1,089	1,041
Net interest income (taxable-equivalent basis), Percent change	5.30%		4.60%
Noninterest income	$ 909	923	$ 1,766	1,739
Noninterest income, Percent change	(1.50%)		1.60%
Securities gains (losses), net, Percent change	0.00%		0.00%
Total net revenue	$ 1,449	1,436	$ 2,855	2,780
Total net revenue, Percent change	0.90%		2.70%
Noninterest expense, Percent change	6.50%		6.40%
Other intangibles, Percent change	3.40%		3.40%
Total noninterest expense, Percent change	6.40%		6.30%
Income before provision and income taxes, Percent change	(4.40%)		(0.90%)
Provision for credit losses, Percent change	31.60%		28.70%
Income before income taxes, Percent change	(19.50%)		(13.30%)
Income taxes and taxable-equivalent adjustment, Percent change	(19.30%)		(13.00%)
Net income, Percent change	(19.60%)		(13.50%)
Net (income) loss attributable to noncontrolling interests, Percent change	25.00%		23.50%
Net income attributable to U.S. Bancorp, Percent change	(19.40%)		(13.20%)
Noninterest expense	$ 722	678	$ 1,423	1,337
Other intangibles	30	29	61	59
Total noninterest expense	752	707	1,484	1,396
Income before provision and income taxes	697	729	1,371	1,384
Provision for credit losses	283	215	524	407
Income before income taxes	414	514	847	977
Income taxes and taxable-equivalent adjustment	151	187	309	355
Net income	263	327	538	622
Net (income) loss attributable to noncontrolling interests	(6)	(8)	(13)	(17)
Net income attributable to U.S. Bancorp	257	319	525	605
Average Balance Sheet
Commercial	$ 7,975	7,522	$ 7,794	7,272
Commercial, Percent change	6.00%		7.20%
Credit card	$ 20,631	20,140	$ 20,737	20,192
Credit card, Percent change	2.40%		2.70%
Other retail	$ 464	531	$ 472	541
Other retail, Percent change	(12.60%)		(12.80%)
Total loans, excluding covered loans	$ 29,070	28,193	$ 29,003	28,005
Total loans, excluding covered loans, Percent change	3.10%		3.60%
Total loans	$ 29,070	28,193	$ 29,003	28,005
Total loans, Percent change	3.10%		3.60%
Goodwill, Percent change	(0.60%)		(0.50%)
Other intangible assets, Percent change	(19.40%)		(16.60%)
Assets, Percent change	2.40%		2.10%
Noninterest-bearing deposits, Percent change	9.70%		8.10%
Savings products, Percent change	5.20%		5.20%
Total deposits, Percent change	9.30%		7.80%
Total U.S. Bancorp shareholders' equity, Percent change	(2.30%)		(0.50%)
Goodwill	$ 2,458	2,472	$ 2,455	2,467
Other intangible assets	408	506	422	506
Assets	34,805	33,997	34,696	33,998
Noninterest-bearing deposits	1,015	925	1,019	943
Savings products	102	97	101	96
Total deposits	1,117	1,022	1,120	1,039
Total U.S. Bancorp shareholders' equity	6,230	6,376	6,318	6,351
Treasury and Corporate Support [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 481	548	$ 938	1,105
Net interest income (taxable-equivalent basis), Percent change	(12.20%)		(15.10%)
Noninterest income	$ 230	339	$ 446	533
Noninterest income, Percent change	(32.20%)		(16.30%)
Securities gains (losses), net	$ 9	3	$ 41	6
Securities gains (losses), net, Percent change	0.00%		0.00%
Total net revenue	$ 720	890	$ 1,425	1,644
Total net revenue, Percent change	(19.10%)		(13.30%)
Noninterest expense, Percent change	(42.60%)		(23.50%)
Total noninterest expense, Percent change	(42.60%)		(23.50%)
Income before provision and income taxes, Percent change	(6.60%)		(9.80%)
Income before income taxes, Percent change	(6.00%)		(9.30%)
Income taxes and taxable-equivalent adjustment, Percent change	3.30%		(59.80%)
Net income, Percent change	(6.50%)		(4.40%)
Net income attributable to U.S. Bancorp, Percent change	(6.60%)		(4.50%)
Noninterest expense	$ 178	310	$ 322	421
Total noninterest expense	178	310	322	421
Income before provision and income taxes	542	580	1,103	1,223
Provision for credit losses	(4)	(1)	(2)	5
Income before income taxes	546	581	1,105	1,218
Income taxes and taxable-equivalent adjustment	31	30	43	107
Net income	515	551	1,062	1,111
Net (income) loss attributable to noncontrolling interests	(6)	(6)	(12)	(12)
Net income attributable to U.S. Bancorp	509	545	1,050	1,099
Average Balance Sheet
Commercial	$ 660	364	$ 636	362
Commercial, Percent change	81.30%		75.70%
Commercial real estate	$ 2,719	3,195	$ 2,753	3,197
Commercial real estate, Percent change	(14.90%)		(13.90%)
Total loans, excluding covered loans	$ 3,379	3,559	$ 3,389	3,559
Total loans, excluding covered loans, Percent change	(5.10%)		(4.80%)
Covered loans	$ 7	35	$ 11	41
Covered loans, Percent change	(80.00%)		(73.20%)
Total loans	$ 3,386	3,594	$ 3,400	3,600
Total loans, Percent change	(5.80%)		(5.60%)
Assets, Percent change	6.70%		6.60%
Noninterest-bearing deposits, Percent change	2.10%		(0.30%)
Interest checking, Percent change	13.60%		2.30%
Savings products, Percent change	(12.20%)		(10.30%)
Time deposits, Percent change	(91.50%)		(93.00%)
Total deposits, Percent change	(47.00%)		(51.20%)
Total U.S. Bancorp shareholders' equity, Percent change	(0.30%)		(0.90%)
Assets	$ 142,529	133,609	$ 140,930	132,209
Noninterest-bearing deposits	2,058	2,016	2,027	2,034
Interest checking	50	44	45	44
Savings products	440	501	446	497
Time deposits	226	2,670	213	3,022
Total deposits	2,774	5,231	2,731	5,597
Total U.S. Bancorp shareholders' equity	$ 18,321	$ 18,375	$ 18,118	$ 18,287