Business Segments - Business Segment Results (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Noninterest income	$ 2,693	$ 2,712	$ 7,693	$ 7,851
Other intangibles	41	44	119	129
Total noninterest expense	3,429	3,371	10,195	10,005
Provision for credit losses	(163)	635	(1,160)	3,365
Net income	2,034	1,586	6,307	3,460
Net (income) loss attributable to noncontrolling interests	(6)	(6)	(17)	(20)
Net income attributable to U.S. Bancorp	2,028	1,580	6,290	3,440
Corporate and Commercial Banking [Member]
Segment Reporting Information [Line Items]
Net interest income (taxable-equivalent basis)	717	852	2,172	2,623
Noninterest income	253	267	786	899
Total net revenue	970	1,119	2,958	3,522
Noninterest expense	418	428	1,257	1,310
Total noninterest expense	418	428	1,257	1,310
Income (loss) before provision and income taxes	552	691	1,701	2,212
Provision for credit losses	15	95	(20)	572
Income (loss) before income taxes	537	596	1,721	1,640
Income taxes and taxable-equivalent adjustment	134	149	430	410
Net income	403	447	1,291	1,230
Net income attributable to U.S. Bancorp	403	447	1,291	1,230
Loans	102,431	115,547	102,117	118,686
Other earning assets	4,722	4,110	4,485	4,170
Goodwill	1,650	1,647	1,648	1,647
Other intangible assets	5	6	5	6
Assets	114,629	128,369	114,182	131,106
Noninterest-bearing deposits	62,642	48,058	59,841	41,091
Interest-bearing deposits	68,917	87,558	69,999	90,581
Total deposits	131,559	135,616	129,840	131,672
Total U.S. Bancorp shareholders' equity	13,772	15,051	13,995	15,201
Consumer and Business Banking [Member]
Segment Reporting Information [Line Items]
Net interest income (taxable-equivalent basis)	1,551	1,474	4,603	4,239
Noninterest income	715	848	1,918	2,433
Total net revenue	2,266	2,322	6,521	6,672
Noninterest expense	1,450	1,383	4,210	4,061
Other intangibles	3	4	9	12
Total noninterest expense	1,453	1,387	4,219	4,073
Income (loss) before provision and income taxes	813	935	2,302	2,599
Provision for credit losses	(25)	69	(143)	269
Income (loss) before income taxes	838	866	2,445	2,330
Income taxes and taxable-equivalent adjustment	210	217	612	583
Net income	628	649	1,833	1,747
Net income attributable to U.S. Bancorp	628	649	1,833	1,747
Loans	140,833	145,229	141,220	139,981
Other earning assets	7,645	8,195	8,606	6,578
Goodwill	3,506	3,475	3,485	3,508
Other intangible assets	2,754	1,942	2,692	2,095
Assets	160,882	164,246	162,316	157,177
Noninterest-bearing deposits	34,416	34,288	33,734	29,397
Interest-bearing deposits	160,271	133,095	156,821	126,934
Total deposits	194,687	167,383	190,555	156,331
Total U.S. Bancorp shareholders' equity	12,277	13,562	12,378	12,797
Wealth Management and Investment Services [Member]
Segment Reporting Information [Line Items]
Net interest income (taxable-equivalent basis)	225	301	721	964
Noninterest income	558	505	1,638	1,507
Total net revenue	783	806	2,359	2,471
Noninterest expense	507	489	1,499	1,445
Other intangibles	4	3	10	9
Total noninterest expense	511	492	1,509	1,454
Income (loss) before provision and income taxes	272	314	850	1,017
Provision for credit losses	11	11	26	34
Income (loss) before income taxes	261	303	824	983
Income taxes and taxable-equivalent adjustment	65	76	206	246
Net income	196	227	618	737
Net income attributable to U.S. Bancorp	196	227	618	737
Loans	18,454	15,616	17,584	15,151
Other earning assets	225	288	247	285
Goodwill	1,618	1,618	1,618	1,617
Other intangible assets	80	37	69	40
Assets	21,566	18,708	20,676	18,324
Noninterest-bearing deposits	24,453	17,719	23,024	16,285
Interest-bearing deposits	71,841	73,857	76,098	76,736
Total deposits	96,294	91,576	99,122	93,021
Total U.S. Bancorp shareholders' equity	3,172	2,968	3,099	2,924
Payments Services [Member]
Segment Reporting Information [Line Items]
Net interest income (taxable-equivalent basis)	616	643	1,841	1,910
Noninterest income	946	867	2,644	2,319
Total net revenue	1,562	1,510	4,485	4,229
Noninterest expense	817	797	2,381	2,296
Other intangibles	34	37	100	108
Total noninterest expense	851	834	2,481	2,404
Income (loss) before provision and income taxes	711	676	2,004	1,825
Provision for credit losses	166	246	216	477
Income (loss) before income taxes	545	430	1,788	1,348
Income taxes and taxable-equivalent adjustment	136	108	447	338
Net income	409	322	1,341	1,010
Net income attributable to U.S. Bancorp	409	322	1,341	1,010
Loans	31,378	31,168	30,353	31,725
Other earning assets	5	5	5	5
Goodwill	3,168	3,123	3,174	3,027
Other intangible assets	496	602	519	584
Assets	37,173	36,191	35,972	36,497
Noninterest-bearing deposits	4,913	6,886	5,068	3,852
Interest-bearing deposits	150	124	141	119
Total deposits	5,063	7,010	5,209	3,971
Total U.S. Bancorp shareholders' equity	7,561	7,716	7,544	7,269
Treasury and Corporate Support [Member]
Segment Reporting Information [Line Items]
Net interest income (taxable-equivalent basis)	88	(18)	113	(13)
Noninterest income	221	225	707	693
Total net revenue	309	207	820	680
Noninterest expense	196	230	729	764
Total noninterest expense	196	230	729	764
Income (loss) before provision and income taxes	113	(23)	91	(84)
Provision for credit losses	(330)	214	(1,239)	2,013
Income (loss) before income taxes	443	(237)	1,330	(2,097)
Income taxes and taxable-equivalent adjustment	45	(178)	106	(833)
Net income	398	(59)	1,224	(1,264)
Net (income) loss attributable to noncontrolling interests	(6)	(6)	(17)	(20)
Net income attributable to U.S. Bancorp	392	(65)	1,207	(1,284)
Loans	3,643	3,458	3,740	3,392
Other earning assets	193,989	162,488	192,259	156,045
Assets	219,196	189,388	218,053	182,276
Noninterest-bearing deposits	2,594	2,424	2,595	2,310
Interest-bearing deposits	1,290	1,514	1,718	3,293
Total deposits	3,884	3,938	4,313	5,603
Total U.S. Bancorp shareholders' equity	17,491	13,119	16,311	13,745
Consolidated Company [Member]
Segment Reporting Information [Line Items]
Net interest income (taxable-equivalent basis)	3,197	3,252	9,450	9,723
Noninterest income	2,693	2,712	7,693	7,851
Total net revenue	5,890	5,964	17,143	17,574
Noninterest expense	3,388	3,327	10,076	9,876
Other intangibles	41	44	119	129
Total noninterest expense	3,429	3,371	10,195	10,005
Income (loss) before provision and income taxes	2,461	2,593	6,948	7,569
Provision for credit losses	(163)	635	(1,160)	3,365
Income (loss) before income taxes	2,624	1,958	8,108	4,204
Income taxes and taxable-equivalent adjustment	590	372	1,801	744
Net income	2,034	1,586	6,307	3,460
Net (income) loss attributable to noncontrolling interests	(6)	(6)	(17)	(20)
Net income attributable to U.S. Bancorp	2,028	1,580	6,290	3,440
Loans	296,739	311,018	295,014	308,935
Other earning assets	206,586	175,086	205,602	167,083
Goodwill	9,942	9,863	9,925	9,799
Other intangible assets	3,335	2,587	3,285	2,725
Assets	553,446	536,902	551,199	525,380
Noninterest-bearing deposits	129,018	109,375	124,262	92,935
Interest-bearing deposits	302,469	296,148	304,777	297,663
Total deposits	431,487	405,523	429,039	390,598
Total U.S. Bancorp shareholders' equity	$ 54,273	$ 52,416	$ 53,327	$ 51,936