Business Segments - Business Segment Results (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting Information [Line Items]
Noninterest income	$ 2,619	$ 2,614	$ 5,000	$ 5,139
Other intangibles	40	43	78	85
Total noninterest expense	3,387	3,318	6,766	6,634
Provision for credit losses	(170)	1,737	(997)	2,730
Net income	1,988	695	4,273	1,874
Net (income) loss attributable to noncontrolling interests	(6)	(6)	(11)	(14)
Net income attributable to U.S. Bancorp	1,982	689	4,262	1,860
Corporate and Commercial Banking [Member]
Segment Reporting Information [Line Items]
Net interest income (taxable-equivalent basis)	683	878	1,355	1,663
Noninterest income	255	339	514	610
Total net revenue	938	1,217	1,869	2,273
Noninterest expense	411	430	816	873
Total noninterest expense	411	430	816	873
Income (loss) before provision and income taxes	527	787	1,053	1,400
Provision for credit losses	23	22	(17)	446
Income (loss) before income taxes	504	765	1,070	954
Income taxes and taxable-equivalent adjustment	126	191	268	238
Net income	378	574	802	716
Net income attributable to U.S. Bancorp	378	574	802	716
Loans	95,145	122,930	95,006	113,147
Other earning assets	4,409	3,847	4,359	4,201
Goodwill	1,647	1,647	1,647	1,647
Other intangible assets	5	6	5	7
Assets	107,058	135,484	107,037	125,394
Noninterest-bearing deposits	54,958	38,749	53,027	34,074
Interest-bearing deposits	66,023	95,388	66,899	88,034
Total deposits	120,981	134,137	119,926	122,108
Total U.S. Bancorp shareholders' equity	13,200	15,274	13,455	14,631
Consumer and Business Banking [Member]
Segment Reporting Information [Line Items]
Net interest income (taxable-equivalent basis)	1,650	1,475	3,277	3,007
Noninterest income	646	886	1,224	1,607
Total net revenue	2,296	2,361	4,501	4,614
Noninterest expense	1,404	1,372	2,783	2,689
Other intangibles	3	4	6	8
Total noninterest expense	1,407	1,376	2,789	2,697
Income (loss) before provision and income taxes	889	985	1,712	1,917
Provision for credit losses	(96)	110	(140)	233
Income (loss) before income taxes	985	875	1,852	1,684
Income taxes and taxable-equivalent adjustment	246	219	463	421
Net income	739	656	1,389	1,263
Net income attributable to U.S. Bancorp	739	656	1,389	1,263
Loans	152,470	150,210	152,822	148,462
Other earning assets	8,033	6,576	9,112	5,772
Goodwill	3,475	3,475	3,475	3,525
Other intangible assets	2,827	1,935	2,660	2,173
Assets	173,285	167,514	174,399	164,690
Noninterest-bearing deposits	40,477	34,499	39,757	31,130
Interest-bearing deposits	174,356	144,158	170,552	138,888
Total deposits	214,833	178,657	210,309	170,018
Total U.S. Bancorp shareholders' equity	13,361	13,752	13,460	13,389
Wealth Management and Investment Services [Member]
Segment Reporting Information [Line Items]
Net interest income (taxable-equivalent basis)	167	250	370	534
Noninterest income	547	499	1,078	1,001
Total net revenue	714	749	1,448	1,535
Noninterest expense	501	474	980	941
Other intangibles	4	3	6	6
Total noninterest expense	505	477	986	947
Income (loss) before provision and income taxes	209	272	462	588
Provision for credit losses	10	(2)	18	21
Income (loss) before income taxes	199	274	444	567
Income taxes and taxable-equivalent adjustment	50	69	111	142
Net income	149	205	333	425
Net income attributable to U.S. Bancorp	149	205	333	425
Loans	12,926	11,206	12,688	10,909
Other earning assets	237	285	258	283
Goodwill	1,618	1,616	1,618	1,617
Other intangible assets	84	40	63	42
Assets	15,916	14,335	15,800	14,153
Noninterest-bearing deposits	22,249	16,396	21,318	14,848
Interest-bearing deposits	61,146	65,466	66,427	67,195
Total deposits	83,395	81,862	87,745	82,043
Total U.S. Bancorp shareholders' equity	2,640	2,481	2,607	2,475
Payments Services [Member]
Segment Reporting Information [Line Items]
Net interest income (taxable-equivalent basis)	596	610	1,225	1,267
Noninterest income	913	658	1,698	1,452
Total net revenue	1,509	1,268	2,923	2,719
Noninterest expense	794	741	1,561	1,495
Other intangibles	33	36	66	71
Total noninterest expense	827	777	1,627	1,566
Income (loss) before provision and income taxes	682	491	1,296	1,153
Provision for credit losses	91	(31)	50	231
Income (loss) before income taxes	591	522	1,246	922
Income taxes and taxable-equivalent adjustment	148	131	312	231
Net income	443	391	934	691
Net income attributable to U.S. Bancorp	443	391	934	691
Loans	30,030	30,321	29,831	32,005
Other earning assets	5	5	5	6
Goodwill	3,177	3,101	3,176	2,977
Other intangible assets	519	590	531	573
Assets	35,620	35,011	35,359	36,647
Noninterest-bearing deposits	5,030	3,165	5,146	2,318
Interest-bearing deposits	141	117	137	116
Total deposits	5,171	3,282	5,283	2,434
Total U.S. Bancorp shareholders' equity	7,413	6,975	7,535	7,042
Treasury and Corporate Support [Member]
Segment Reporting Information [Line Items]
Net interest income (taxable-equivalent basis)	68	11	26
Noninterest income	258	232	486	469
Total net revenue	326	243	512	469
Noninterest expense	237	258	548	551
Total noninterest expense	237	258	548	551
Income (loss) before provision and income taxes	89	(15)	(36)	(82)
Provision for credit losses	(198)	1,638	(908)	1,799
Income (loss) before income taxes	287	(1,653)	872	(1,881)
Income taxes and taxable-equivalent adjustment	8	(522)	57	(660)
Net income	279	(1,131)	815	(1,221)
Net (income) loss attributable to noncontrolling interests	(6)	(6)	(11)	(14)
Net income attributable to U.S. Bancorp	273	(1,137)	804	(1,235)
Loans	3,713	3,440	3,791	3,359
Other earning assets	193,783	165,299	191,367	152,777
Assets	219,486	191,962	217,462	178,672
Noninterest-bearing deposits	2,583	2,297	2,596	2,254
Interest-bearing deposits	2,247	3,068	1,936	4,196
Total deposits	4,830	5,365	4,532	6,450
Total U.S. Bancorp shareholders' equity	16,348	13,759	15,789	14,156
Consolidated Company [Member]
Segment Reporting Information [Line Items]
Net interest income (taxable-equivalent basis)	3,164	3,224	6,253	6,471
Noninterest income	2,619	2,614	5,000	5,139
Total net revenue	5,783	5,838	11,253	11,610
Noninterest expense	3,347	3,275	6,688	6,549
Other intangibles	40	43	78	85
Total noninterest expense	3,387	3,318	6,766	6,634
Income (loss) before provision and income taxes	2,396	2,520	4,487	4,976
Provision for credit losses	(170)	1,737	(997)	2,730
Income (loss) before income taxes	2,566	783	5,484	2,246
Income taxes and taxable-equivalent adjustment	578	88	1,211	372
Net income	1,988	695	4,273	1,874
Net (income) loss attributable to noncontrolling interests	(6)	(6)	(11)	(14)
Net income attributable to U.S. Bancorp	1,982	689	4,262	1,860
Loans	294,284	318,107	294,138	307,882
Other earning assets	206,467	176,012	205,101	163,039
Goodwill	9,917	9,839	9,916	9,766
Other intangible assets	3,435	2,571	3,259	2,795
Assets	551,365	544,306	550,057	519,556
Noninterest-bearing deposits	125,297	95,106	121,844	84,624
Interest-bearing deposits	303,913	308,197	305,951	298,429
Total deposits	429,210	403,303	427,795	383,053
Total U.S. Bancorp shareholders' equity	$ 52,962	$ 52,241	$ 52,846	$ 51,693