Basis of Presentation - Line of Business Financial Performance (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 2,896	$ 2,770	$ 5,784	$ 5,522
Net interest income (taxable-equivalent basis), Percent change	4.50%		4.70%
Noninterest income	$ 2,549	2,272	$ 4,695	4,426
Noninterest income, Percent change	12.20%		6.10%
Securities gains (losses), net	$ 3		$ 6
Securities gains (losses), net, Percent change	0.00%		0.00%
Total net revenue	$ 5,448	5,042	$ 10,485	9,948
Total net revenue, Percent change	8.10%		5.40%
Noninterest expense, Percent change	11.70%		7.40%
Other intangibles, Percent change	2.30%		3.50%
Total noninterest expense, Percent change	11.60%		7.40%
Income before provision and income taxes, Percent change	4.10%		3.10%
Provision for credit losses, Percent change	16.40%		20.60%
Income before income taxes, Percent change	2.40%		0.80%
Income taxes and taxable-equivalent adjustment, Percent change	1.90%		3.10%
Net income, Percent change	2.60%		(0.10%)
Net (income) loss attributable to noncontrolling interests, Percent change			(7.40%)
Net income attributable to U.S. Bancorp, Percent change	2.60%		(0.20%)
Noninterest expense	$ 2,948	2,639	$ 5,652	5,261
Other intangibles	44	43	89	86
Total noninterest expense	2,992	2,682	5,741	5,347
Income before provision and income taxes	2,456	2,360	4,744	4,601
Provision for credit losses	327	281	657	545
Income before income taxes	2,129	2,079	4,087	4,056
Income taxes and taxable-equivalent adjustment	593	582	1,150	1,115
Net income	1,536	1,497	2,937	2,941
Net (income) loss attributable to noncontrolling interests	(14)	(14)	(29)	(27)
Net income attributable to U.S. Bancorp	1,522	1,483	2,908	2,914
Average Balance Sheet
Commercial	$ 92,154	83,253	$ 90,987	82,385
Commercial, Percent change	10.70%		10.40%
Commercial real estate	$ 42,988	42,446	$ 42,694	42,558
Commercial real estate, Percent change	1.30%		0.30%
Residential mortgages	$ 55,501	51,114	$ 54,854	51,269
Residential mortgages, Percent change	8.60%		7.00%
Credit card	$ 20,140	17,613	$ 20,192	17,718
Credit card, Percent change	14.30%		14.00%
Other retail	$ 51,468	47,069	$ 51,283	48,188
Other retail, Percent change	9.30%		6.40%
Total loans, excluding covered loans	$ 262,251	241,495	$ 260,010	242,118
Total loans, excluding covered loans, Percent change	8.60%		7.40%
Covered loans	$ 4,331	5,065	$ 4,422	5,133
Covered loans, Percent change	(14.50%)		(13.90%)
Total loans	$ 266,582	246,560	$ 264,432	247,251
Total loans, Percent change	8.10%		6.90%
Goodwill, Percent change			(0.10%)
Other intangible assets, Percent change	(2.90%)		(0.30%)
Assets, Percent change	5.10%		5.00%
Noninterest-bearing deposits, Percent change	2.40%		3.90%
Interest checking, Percent change	10.20%		8.10%
Savings products, Percent change	13.80%		14.10%
Time deposits, Percent change	(5.60%)		(10.20%)
Total deposits, Percent change	7.60%		6.90%
Total U.S. Bancorp shareholders' equity, Percent change	6.00%		6.00%
Goodwill	$ 9,368	9,369	$ 9,363	9,373
Other intangible assets	3,026	3,117	3,087	3,097
Assets	428,750	407,901	425,153	404,885
Noninterest-bearing deposits	79,171	77,347	78,870	75,937
Interest checking	60,842	55,205	59,376	54,933
Savings products	133,162	116,969	129,437	113,465
Time deposits	34,211	36,223	33,949	37,787
Total deposits	307,386	285,744	301,632	282,122
Total U.S. Bancorp shareholders' equity	47,184	44,514	46,961	44,297
Wholesale Banking and Commercial Real Estate [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 537	487	$ 1,058	967
Net interest income (taxable-equivalent basis), Percent change	10.30%		9.40%
Noninterest income	$ 249	224	$ 455	444
Noninterest income, Percent change	11.20%		2.50%
Securities gains (losses), net, Percent change	0.00%		0.00%
Total net revenue	$ 786	711	$ 1,513	1,411
Total net revenue, Percent change	10.50%		7.20%
Noninterest expense, Percent change	9.60%		6.80%
Total noninterest expense, Percent change	9.60%		6.70%
Income before provision and income taxes, Percent change	11.40%		7.60%
Income before income taxes, Percent change	(1.10%)		(19.60%)
Income taxes and taxable-equivalent adjustment, Percent change	(1.50%)		(20.00%)
Net income, Percent change	(0.90%)		(19.30%)
Net income attributable to U.S. Bancorp, Percent change	(0.90%)		(19.30%)
Noninterest expense	$ 354	323	$ 694	650
Other intangibles	1	1	2	2
Total noninterest expense	355	324	696	652
Income before provision and income taxes	431	387	817	759
Provision for credit losses	65	17	266	74
Income before income taxes	366	370	551	685
Income taxes and taxable-equivalent adjustment	133	135	200	250
Net income	233	235	351	435
Net income attributable to U.S. Bancorp	233	235	351	435
Average Balance Sheet
Commercial	$ 70,782	63,329	$ 70,067	63,023
Commercial, Percent change	11.80%		11.20%
Commercial real estate	$ 19,932	19,457	$ 19,698	19,351
Commercial real estate, Percent change	2.40%		1.80%
Residential mortgages	$ 7	8	$ 7	8
Residential mortgages, Percent change	(12.50%)		(12.50%)
Other retail	$ 2	3	$ 2	3
Other retail, Percent change	(33.30%)		(33.30%)
Total loans, excluding covered loans	$ 90,723	82,797	$ 89,774	82,385
Total loans, excluding covered loans, Percent change	9.60%		9.00%
Total loans	$ 90,723	82,797	$ 89,774	82,385
Total loans, Percent change	9.60%		9.00%
Other intangible assets, Percent change	(19.00%)		(14.30%)
Assets, Percent change	8.20%		7.80%
Noninterest-bearing deposits, Percent change	1.50%		3.50%
Interest checking, Percent change	8.20%		(1.40%)
Savings products, Percent change	47.00%		43.80%
Time deposits, Percent change	(13.50%)		(21.80%)
Total deposits, Percent change	13.80%		10.70%
Total U.S. Bancorp shareholders' equity, Percent change	9.70%		9.20%
Goodwill	$ 1,647	1,647	$ 1,647	1,647
Other intangible assets	17	21	18	21
Assets	99,195	91,670	98,223	91,086
Noninterest-bearing deposits	35,852	35,324	36,131	34,903
Interest checking	8,094	7,480	7,475	7,578
Savings products	39,894	27,140	37,841	26,324
Time deposits	13,384	15,465	12,752	16,300
Total deposits	97,224	85,409	94,199	85,105
Total U.S. Bancorp shareholders' equity	8,900	8,116	8,828	8,083
Consumer and Small Business Banking [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 1,179	1,141	$ 2,346	2,280
Net interest income (taxable-equivalent basis), Percent change	3.30%		2.90%
Noninterest income	$ 638	629	$ 1,190	1,249
Noninterest income, Percent change	1.40%		(4.70%)
Securities gains (losses), net, Percent change	0.00%		0.00%
Total net revenue	$ 1,817	1,770	$ 3,536	3,529
Total net revenue, Percent change	2.70%		0.20%
Noninterest expense, Percent change	2.10%		2.20%
Other intangibles, Percent change	(20.00%)		(20.00%)
Total noninterest expense, Percent change	1.90%		2.00%
Income before provision and income taxes, Percent change	4.30%		(3.60%)
Provision for credit losses, Percent change	(7.80%)
Income before income taxes, Percent change	5.50%		3.90%
Income taxes and taxable-equivalent adjustment, Percent change	5.40%		3.80%
Net income, Percent change	5.50%		3.90%
Net income attributable to U.S. Bancorp, Percent change	5.50%		3.90%
Noninterest expense	$ 1,223	1,198	$ 2,423	2,371
Other intangibles	8	10	16	20
Total noninterest expense	1,231	1,208	2,439	2,391
Income before provision and income taxes	586	562	1,097	1,138
Provision for credit losses	47	51	(20)	63
Income before income taxes	539	511	1,117	1,075
Income taxes and taxable-equivalent adjustment	196	186	406	391
Net income	343	325	711	684
Net income attributable to U.S. Bancorp	343	325	711	684
Average Balance Sheet
Commercial	$ 10,653	10,304	$ 10,423	9,975
Commercial, Percent change	3.40%		4.50%
Commercial real estate	$ 19,344	18,930	$ 19,273	19,058
Commercial real estate, Percent change	2.20%		1.10%
Residential mortgages	$ 53,316	49,337	$ 52,720	49,553
Residential mortgages, Percent change	8.10%		6.40%
Other retail	$ 49,414	44,953	$ 49,209	46,090
Other retail, Percent change	9.90%		6.80%
Total loans, excluding covered loans	$ 132,727	123,524	$ 131,625	124,676
Total loans, excluding covered loans, Percent change	7.50%		5.60%
Covered loans	$ 4,296	5,020	$ 4,381	5,091
Covered loans, Percent change	(14.40%)		(13.90%)
Total loans	$ 137,023	128,544	$ 136,006	129,767
Total loans, Percent change	6.60%		4.80%
Other intangible assets, Percent change	(6.40%)		(2.90%)
Assets, Percent change	3.00%		2.50%
Noninterest-bearing deposits, Percent change	5.90%		5.90%
Interest checking, Percent change	8.90%		8.50%
Savings products, Percent change	7.00%		7.00%
Time deposits, Percent change	(11.00%)		(12.30%)
Total deposits, Percent change	5.20%		4.90%
Total U.S. Bancorp shareholders' equity, Percent change	3.20%		(0.40%)
Goodwill	$ 3,681	3,681	$ 3,681	3,681
Other intangible assets	2,399	2,564	2,455	2,529
Assets	151,947	147,472	150,633	146,993
Noninterest-bearing deposits	27,306	25,774	26,790	25,289
Interest checking	43,572	40,029	42,865	39,513
Savings products	57,324	53,576	56,756	53,020
Time deposits	14,250	16,018	14,449	16,482
Total deposits	142,452	135,397	140,860	134,304
Total U.S. Bancorp shareholders' equity	11,153	10,809	11,119	11,167
Wealth Management and Securities Services [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 122	82	$ 239	162
Net interest income (taxable-equivalent basis), Percent change	48.80%		47.50%
Noninterest income	$ 401	374	$ 780	732
Noninterest income, Percent change	7.20%		6.60%
Securities gains (losses), net, Percent change	0.00%		0.00%
Total net revenue	$ 523	456	$ 1,019	894
Total net revenue, Percent change	14.70%		14.00%
Noninterest expense, Percent change	3.20%		3.60%
Other intangibles, Percent change	(14.30%)		(14.30%)
Total noninterest expense, Percent change	2.80%		3.20%
Income before provision and income taxes, Percent change	56.40%		57.00%
Income before income taxes, Percent change	57.00%		56.70%
Income taxes and taxable-equivalent adjustment, Percent change	58.30%		56.90%
Net income, Percent change	56.30%		56.50%
Net income attributable to U.S. Bancorp, Percent change	56.30%		56.50%
Noninterest expense	$ 359	348	$ 726	701
Other intangibles	6	7	12	14
Total noninterest expense	365	355	738	715
Income before provision and income taxes	158	101	281	179
Provision for credit losses	1	1	(1)	(1)
Income before income taxes	157	100	282	180
Income taxes and taxable-equivalent adjustment	57	36	102	65
Net income	100	64	180	115
Net income attributable to U.S. Bancorp	100	64	180	115
Average Balance Sheet
Commercial	$ 2,835	2,256	$ 2,864	2,274
Commercial, Percent change	25.70%		25.90%
Commercial real estate	$ 517	553	$ 526	569
Commercial real estate, Percent change	(6.50%)		(7.60%)
Residential mortgages	$ 2,178	1,756	$ 2,127	1,695
Residential mortgages, Percent change	24.00%		25.50%
Other retail	$ 1,521	1,511	$ 1,531	1,481
Other retail, Percent change	0.70%		3.40%
Total loans, excluding covered loans	$ 7,051	6,076	$ 7,048	6,019
Total loans, excluding covered loans, Percent change	16.00%		17.10%
Covered loans		1		1
Total loans	$ 7,051	6,077	$ 7,048	6,020
Total loans, Percent change	16.00%		17.10%
Goodwill, Percent change	0.10%
Other intangible assets, Percent change	(19.40%)		(19.50%)
Assets, Percent change	11.40%		11.00%
Noninterest-bearing deposits, Percent change	(4.60%)		(1.60%)
Interest checking, Percent change	29.40%		24.70%
Savings products, Percent change	(0.90%)		2.10%
Time deposits, Percent change	11.70%		14.70%
Total deposits, Percent change	2.50%		4.80%
Total U.S. Bancorp shareholders' equity, Percent change	3.30%		3.20%
Goodwill	$ 1,568	1,567	$ 1,567	1,567
Other intangible assets	104	129	107	133
Assets	10,005	8,983	10,089	9,091
Noninterest-bearing deposits	13,076	13,706	12,976	13,188
Interest checking	9,136	7,061	8,996	7,215
Savings products	35,353	35,684	34,253	33,553
Time deposits	3,907	3,498	3,726	3,248
Total deposits	61,472	59,949	59,951	57,204
Total U.S. Bancorp shareholders' equity	2,381	2,304	2,376	2,302
Payment Services [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 513	459	$ 1,040	926
Net interest income (taxable-equivalent basis), Percent change	11.80%		12.30%
Noninterest income	$ 923	850	$ 1,739	1,627
Noninterest income, Percent change	8.60%		6.90%
Securities gains (losses), net, Percent change	0.00%		0.00%
Total net revenue	$ 1,436	1,309	$ 2,779	2,553
Total net revenue, Percent change	9.70%		8.90%
Noninterest expense, Percent change	0.20%		4.00%
Other intangibles, Percent change	16.00%		18.00%
Total noninterest expense, Percent change	0.70%		4.60%
Income before provision and income taxes, Percent change	19.60%		13.40%
Provision for credit losses, Percent change	3.40%		0.50%
Income before income taxes, Percent change	27.80%		19.60%
Income taxes and taxable-equivalent adjustment, Percent change	28.00%		19.70%
Net income, Percent change	27.80%		19.50%
Net (income) loss attributable to noncontrolling interests, Percent change			(6.30%)
Net income attributable to U.S. Bancorp, Percent change	28.60%		19.90%
Noninterest expense	$ 664	663	$ 1,312	1,261
Other intangibles	29	25	59	50
Total noninterest expense	693	688	1,371	1,311
Income before provision and income taxes	743	621	1,408	1,242
Provision for credit losses	215	208	407	405
Income before income taxes	528	413	1,001	837
Income taxes and taxable-equivalent adjustment	192	150	364	304
Net income	336	263	637	533
Net (income) loss attributable to noncontrolling interests	(8)	(8)	(17)	(16)
Net income attributable to U.S. Bancorp	328	255	620	517
Average Balance Sheet
Commercial	$ 7,522	7,083	$ 7,272	6,840
Commercial, Percent change	6.20%		6.30%
Credit card	$ 20,140	17,613	$ 20,192	17,718
Credit card, Percent change	14.30%		14.00%
Other retail	$ 531	602	$ 541	614
Other retail, Percent change	(11.80%)		(11.90%)
Total loans, excluding covered loans	$ 28,193	25,298	$ 28,005	25,172
Total loans, excluding covered loans, Percent change	11.40%		11.30%
Total loans	$ 28,193	25,298	$ 28,005	25,172
Total loans, Percent change	11.40%		11.30%
Goodwill, Percent change	(0.10%)		(0.40%)
Other intangible assets, Percent change	25.60%		22.50%
Assets, Percent change	7.90%		8.80%
Noninterest-bearing deposits, Percent change	5.00%		6.40%
Savings products, Percent change	7.80%		7.90%
Total deposits, Percent change	(35.00%)		(33.80%)
Total U.S. Bancorp shareholders' equity, Percent change	9.60%		9.50%
Goodwill	$ 2,472	2,474	$ 2,468	2,478
Other intangible assets	506	403	507	414
Assets	33,997	31,510	33,998	31,250
Noninterest-bearing deposits	925	881	943	886
Interest checking		602		595
Savings products	97	90	96	89
Total deposits	1,022	1,573	1,039	1,570
Total U.S. Bancorp shareholders' equity	6,376	5,817	6,351	5,799
Treasury and Corporate Support [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 545	601	$ 1,101	1,187
Net interest income (taxable-equivalent basis), Percent change	(9.30%)		(7.20%)
Noninterest income	$ 338	195	$ 531	374
Noninterest income, Percent change	73.30%		42.00%
Securities gains (losses), net	$ 3		$ 6
Securities gains (losses), net, Percent change	0.00%		0.00%
Total net revenue	$ 886	796	$ 1,638	1,561
Total net revenue, Percent change	11.30%		4.90%
Noninterest expense, Percent change			78.80%
Total noninterest expense, Percent change			78.80%
Income before provision and income taxes, Percent change	(21.90%)		(11.10%)
Provision for credit losses, Percent change			25.00%
Income before income taxes, Percent change	(21.30%)		(11.20%)
Income taxes and taxable-equivalent adjustment, Percent change	(80.00%)		(25.70%)
Net income, Percent change	(14.10%)		(9.90%)
Net (income) loss attributable to noncontrolling interests, Percent change			(9.10%)
Net income attributable to U.S. Bancorp, Percent change	(14.20%)		(10.10%)
Noninterest expense	$ 348	107	$ 497	278
Total noninterest expense	348	107	497	278
Income before provision and income taxes	538	689	1,141	1,283
Provision for credit losses	(1)	4	5	4
Income before income taxes	539	685	1,136	1,279
Income taxes and taxable-equivalent adjustment	15	75	78	105
Net income	524	610	1,058	1,174
Net (income) loss attributable to noncontrolling interests	(6)	(6)	(12)	(11)
Net income attributable to U.S. Bancorp	518	604	1,046	1,163
Average Balance Sheet
Commercial	$ 362	281	$ 361	273
Commercial, Percent change	28.80%		32.20%
Commercial real estate	$ 3,195	3,506	$ 3,197	3,580
Commercial real estate, Percent change	(8.90%)		(10.70%)
Residential mortgages		13		13
Total loans, excluding covered loans	$ 3,557	3,800	$ 3,558	3,866
Total loans, excluding covered loans, Percent change	(6.40%)		(8.00%)
Covered loans	$ 35	44	$ 41	41
Covered loans, Percent change	(20.50%)
Total loans	$ 3,592	3,844	$ 3,599	3,907
Total loans, Percent change	(6.60%)		(7.90%)
Assets, Percent change	4.20%		4.50%
Noninterest-bearing deposits, Percent change	21.10%		21.50%
Interest checking, Percent change	21.20%		25.00%
Savings products, Percent change	3.10%		2.50%
Time deposits, Percent change			72.00%
Total deposits, Percent change	52.70%		41.70%
Total U.S. Bancorp shareholders' equity, Percent change	5.20%		7.90%
Assets	$ 133,606	128,266	$ 132,210	126,465
Noninterest-bearing deposits	2,012	1,662	2,030	1,671
Interest checking	40	33	40	32
Savings products	494	479	491	479
Time deposits	2,670	1,242	3,022	1,757
Total deposits	5,216	3,416	5,583	3,939
Total U.S. Bancorp shareholders' equity	$ 18,374	$ 17,468	$ 18,287	$ 16,946