Basis of Presentation - Line of Business Financial Performance (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 2,888	$ 2,752
Net interest income (taxable-equivalent basis), Percent change	4.90%
Noninterest income	$ 2,146	2,154
Noninterest income, Percent change	(0.40%)
Securities gains (losses), net	$ 3
Securities gains (losses), net, Percent change	0.00%
Total net revenue	$ 5,037	4,906
Total net revenue, Percent change	2.70%
Noninterest expense, Percent change	3.10%
Other intangibles, Percent change	4.70%
Total noninterest expense, Percent change	3.20%
Income before provision and income taxes, Percent change	2.10%
Provision for credit losses, Percent change	25.00%
Income before income taxes, Percent change	(1.00%)
Income taxes and taxable-equivalent adjustment, Percent change	4.50%
Net income, Percent change	(3.00%)
Net (income) loss attributable to noncontrolling interests, Percent change	(15.40%)
Net income attributable to U.S. Bancorp, Percent change	(3.10%)
Noninterest expense	$ 2,704	2,622
Other intangibles	45	43
Total noninterest expense	2,749	2,665
Income before provision and income taxes	2,288	2,241
Provision for credit losses	330	264
Income before income taxes	1,958	1,977
Income taxes and taxable-equivalent adjustment	557	533
Net income	1,401	1,444
Net (income) loss attributable to noncontrolling interests	(15)	(13)
Net income attributable to U.S. Bancorp	1,386	1,431
Average Balance Sheet
Commercial	$ 89,820	81,508
Commercial, Percent change	10.20%
Commercial real estate	$ 42,401	42,671
Commercial real estate, Percent change	(0.60%)
Residential mortgages	$ 54,208	51,426
Residential mortgages, Percent change	5.40%
Credit card	$ 20,244	17,823
Credit card, Percent change	13.60%
Other retail	$ 51,097	49,320
Other retail, Percent change	3.60%
Total loans, excluding covered loans	$ 257,770	242,748
Total loans, excluding covered loans, Percent change	6.20%
Covered loans	$ 4,511	5,202
Covered loans, Percent change	(13.30%)
Total loans	$ 262,281	247,950
Total loans, Percent change	5.80%
Goodwill, Percent change	(0.20%)
Other intangible assets, Percent change	2.30%
Assets, Percent change	4.90%
Noninterest-bearing deposits, Percent change	5.40%
Interest checking, Percent change	5.90%
Savings products, Percent change	14.40%
Time deposits, Percent change	(14.40%)
Total deposits, Percent change	6.30%
Total U.S. Bancorp shareholders' equity, Percent change	6.00%
Goodwill	$ 9,359	9,378
Other intangible assets	3,148	3,076
Assets	421,557	401,836
Noninterest-bearing deposits	78,569	74,511
Interest checking	57,910	54,658
Savings products	125,712	109,922
Time deposits	33,687	39,369
Total deposits	295,878	278,460
Total U.S. Bancorp shareholders' equity	46,738	44,078
Wholesale Banking and Commercial Real Estate [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 520	480
Net interest income (taxable-equivalent basis), Percent change	8.30%
Noninterest income	$ 206	220
Noninterest income, Percent change	(6.40%)
Securities gains (losses), net, Percent change	0.00%
Total net revenue	$ 726	700
Total net revenue, Percent change	3.70%
Noninterest expense, Percent change	3.40%
Total noninterest expense, Percent change	3.40%
Income before provision and income taxes, Percent change	4.00%
Income before income taxes, Percent change	(41.00%)
Income taxes and taxable-equivalent adjustment, Percent change	(40.90%)
Net income, Percent change	(41.00%)
Net income attributable to U.S. Bancorp, Percent change	(41.00%)
Noninterest expense	$ 338	327
Other intangibles	1	1
Total noninterest expense	339	328
Income before provision and income taxes	387	372
Provision for credit losses	201	57
Income before income taxes	186	315
Income taxes and taxable-equivalent adjustment	68	115
Net income	118	200
Net income attributable to U.S. Bancorp	118	200
Average Balance Sheet
Commercial	$ 69,353	62,714
Commercial, Percent change	10.60%
Commercial real estate	$ 19,471	19,247
Commercial real estate, Percent change	1.20%
Residential mortgages	$ 6	9
Residential mortgages, Percent change	(33.30%)
Other retail	$ 2	3
Other retail, Percent change	(33.30%)
Total loans, excluding covered loans	$ 88,832	81,973
Total loans, excluding covered loans, Percent change	8.40%
Total loans	$ 88,832	81,973
Total loans, Percent change	8.40%
Goodwill, Percent change	(0.10%)
Other intangible assets, Percent change	(14.30%)
Assets, Percent change	7.50%
Noninterest-bearing deposits, Percent change	5.60%
Interest checking, Percent change	(10.70%)
Savings products, Percent change	40.40%
Time deposits, Percent change	(29.30%)
Total deposits, Percent change	7.50%
Total U.S. Bancorp shareholders' equity, Percent change	8.80%
Goodwill	$ 1,647	1,648
Other intangible assets	18	21
Assets	97,255	90,501
Noninterest-bearing deposits	36,352	34,428
Interest checking	6,850	7,674
Savings products	35,774	25,486
Time deposits	12,118	17,142
Total deposits	91,094	84,730
Total U.S. Bancorp shareholders' equity	8,755	8,049
Consumer and Small Business Banking [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 1,167	1,139
Net interest income (taxable-equivalent basis), Percent change	2.50%
Noninterest income	$ 552	620
Noninterest income, Percent change	(11.00%)
Securities gains (losses), net, Percent change	0.00%
Total net revenue	$ 1,719	1,759
Total net revenue, Percent change	(2.30%)
Noninterest expense, Percent change	2.00%
Other intangibles, Percent change	(20.00%)
Total noninterest expense, Percent change	1.90%
Income before provision and income taxes, Percent change	(10.80%)
Income before income taxes, Percent change	2.70%
Income taxes and taxable-equivalent adjustment, Percent change	2.40%
Net income, Percent change	2.80%
Net income attributable to U.S. Bancorp, Percent change	2.80%
Noninterest expense	$ 1,198	1,174
Other intangibles	8	10
Total noninterest expense	1,206	1,184
Income before provision and income taxes	513	575
Provision for credit losses	(65)	12
Income before income taxes	578	563
Income taxes and taxable-equivalent adjustment	210	205
Net income	368	358
Net income attributable to U.S. Bancorp	368	358
Average Balance Sheet
Commercial	$ 10,192	9,642
Commercial, Percent change	5.70%
Commercial real estate	$ 19,197	19,183
Commercial real estate, Percent change	0.10%
Residential mortgages	$ 52,126	49,771
Residential mortgages, Percent change	4.70%
Other retail	$ 49,004	47,239
Other retail, Percent change	3.70%
Total loans, excluding covered loans	$ 130,519	125,835
Total loans, excluding covered loans, Percent change	3.70%
Covered loans	$ 4,466	5,163
Covered loans, Percent change	(13.50%)
Total loans	$ 134,985	130,998
Total loans, Percent change	3.00%
Other intangible assets, Percent change	0.80%
Assets, Percent change	1.90%
Noninterest-bearing deposits, Percent change	6.00%
Interest checking, Percent change	8.10%
Savings products, Percent change	7.10%
Time deposits, Percent change	(13.60%)
Total deposits, Percent change	4.60%
Total U.S. Bancorp shareholders' equity, Percent change	(3.90%)
Goodwill	$ 3,681	3,680
Other intangible assets	2,513	2,493
Assets	149,320	146,503
Noninterest-bearing deposits	26,303	24,819
Interest checking	42,180	39,013
Savings products	56,211	52,472
Time deposits	14,651	16,952
Total deposits	139,345	133,256
Total U.S. Bancorp shareholders' equity	11,084	11,529
Wealth Management and Securities Services [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 117	80
Net interest income (taxable-equivalent basis), Percent change	46.30%
Noninterest income	$ 379	358
Noninterest income, Percent change	5.90%
Securities gains (losses), net, Percent change	0.00%
Total net revenue	$ 496	438
Total net revenue, Percent change	13.20%
Noninterest expense, Percent change	4.20%
Other intangibles, Percent change	(14.30%)
Total noninterest expense, Percent change	3.90%
Income before provision and income taxes, Percent change	56.40%
Income before income taxes, Percent change	57.50%
Income taxes and taxable-equivalent adjustment, Percent change	58.60%
Net income, Percent change	56.90%
Net income attributable to U.S. Bancorp, Percent change	56.90%
Noninterest expense	$ 368	353
Other intangibles	6	7
Total noninterest expense	374	360
Income before provision and income taxes	122	78
Provision for credit losses	(4)	(2)
Income before income taxes	126	80
Income taxes and taxable-equivalent adjustment	46	29
Net income	80	51
Net income attributable to U.S. Bancorp	80	51
Average Balance Sheet
Commercial	$ 2,893	2,292
Commercial, Percent change	26.20%
Commercial real estate	$ 535	586
Commercial real estate, Percent change	(8.70%)
Residential mortgages	$ 2,076	1,634
Residential mortgages, Percent change	27.10%
Other retail	$ 1,540	1,451
Other retail, Percent change	6.10%
Total loans, excluding covered loans	$ 7,044	5,963
Total loans, excluding covered loans, Percent change	18.10%
Covered loans		1
Total loans	$ 7,044	5,964
Total loans, Percent change	18.10%
Goodwill, Percent change	(0.10%)
Other intangible assets, Percent change	(20.40%)
Assets, Percent change	10.60%
Noninterest-bearing deposits, Percent change	1.60%
Interest checking, Percent change	20.20%
Savings products, Percent change	5.60%
Time deposits, Percent change	18.30%
Total deposits, Percent change	7.30%
Total U.S. Bancorp shareholders' equity, Percent change	3.10%
Goodwill	$ 1,567	1,568
Other intangible assets	109	137
Assets	10,172	9,201
Noninterest-bearing deposits	12,959	12,750
Interest checking	8,840	7,354
Savings products	33,144	31,399
Time deposits	3,545	2,997
Total deposits	58,488	54,500
Total U.S. Bancorp shareholders' equity	2,371	2,299
Payment Services [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 527	467
Net interest income (taxable-equivalent basis), Percent change	12.80%
Noninterest income	$ 816	777
Noninterest income, Percent change	5.00%
Securities gains (losses), net, Percent change	0.00%
Total net revenue	$ 1,343	1,244
Total net revenue, Percent change	8.00%
Noninterest expense, Percent change	8.20%
Other intangibles, Percent change	20.00%
Total noninterest expense, Percent change	8.70%
Income before provision and income taxes, Percent change	7.20%
Provision for credit losses, Percent change	(2.50%)
Income before income taxes, Percent change	11.80%
Income taxes and taxable-equivalent adjustment, Percent change	11.70%
Net income, Percent change	11.90%
Net (income) loss attributable to noncontrolling interests, Percent change	(12.50%)
Net income attributable to U.S. Bancorp, Percent change	11.80%
Noninterest expense	$ 647	598
Other intangibles	30	25
Total noninterest expense	677	623
Income before provision and income taxes	666	621
Provision for credit losses	192	197
Income before income taxes	474	424
Income taxes and taxable-equivalent adjustment	172	154
Net income	302	270
Net (income) loss attributable to noncontrolling interests	(9)	(8)
Net income attributable to U.S. Bancorp	293	262
Average Balance Sheet
Commercial	$ 7,022	6,595
Commercial, Percent change	6.50%
Credit card	$ 20,244	17,823
Credit card, Percent change	13.60%
Other retail	$ 551	627
Other retail, Percent change	(12.10%)
Total loans, excluding covered loans	$ 27,817	25,045
Total loans, excluding covered loans, Percent change	11.10%
Total loans	$ 27,817	25,045
Total loans, Percent change	11.10%
Goodwill, Percent change	(0.70%)
Other intangible assets, Percent change	19.50%
Assets, Percent change	9.70%
Noninterest-bearing deposits, Percent change	7.70%
Savings products, Percent change	9.20%
Total deposits, Percent change	(32.60%)
Total U.S. Bancorp shareholders' equity, Percent change	9.40%
Goodwill	$ 2,464	2,482
Other intangible assets	508	425
Assets	33,999	30,988
Noninterest-bearing deposits	961	892
Interest checking		587
Savings products	95	87
Total deposits	1,056	1,566
Total U.S. Bancorp shareholders' equity	6,326	5,780
Treasury and Corporate Support [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 557	586
Net interest income (taxable-equivalent basis), Percent change	(4.90%)
Noninterest income	$ 193	179
Noninterest income, Percent change	7.80%
Securities gains (losses), net	$ 3
Securities gains (losses), net, Percent change	0.00%
Total net revenue	$ 753	765
Total net revenue, Percent change	(1.60%)
Noninterest expense, Percent change	(10.00%)
Total noninterest expense, Percent change	(10.00%)
Income before provision and income taxes, Percent change	0.80%
Income before income taxes, Percent change	(0.20%)
Net income, Percent change	(5.70%)
Net (income) loss attributable to noncontrolling interests, Percent change	(20.00%)
Net income attributable to U.S. Bancorp, Percent change	(5.90%)
Noninterest expense	$ 153	170
Total noninterest expense	153	170
Income before provision and income taxes	600	595
Provision for credit losses	6
Income before income taxes	594	595
Income taxes and taxable-equivalent adjustment	61	30
Net income	533	565
Net (income) loss attributable to noncontrolling interests	(6)	(5)
Net income attributable to U.S. Bancorp	527	560
Average Balance Sheet
Commercial	$ 360	265
Commercial, Percent change	35.80%
Commercial real estate	$ 3,198	3,655
Commercial real estate, Percent change	(12.50%)
Residential mortgages		12
Total loans, excluding covered loans	$ 3,558	3,932
Total loans, excluding covered loans, Percent change	(9.50%)
Covered loans	$ 45	38
Covered loans, Percent change	18.40%
Total loans	$ 3,603	3,970
Total loans, Percent change	(9.20%)
Assets, Percent change	4.90%
Noninterest-bearing deposits, Percent change	22.90%
Interest checking, Percent change	33.30%
Savings products, Percent change	2.10%
Time deposits, Percent change	48.10%
Total deposits, Percent change	33.70%
Total U.S. Bancorp shareholders' equity, Percent change	10.80%
Assets	$ 130,811	124,643
Noninterest-bearing deposits	1,994	1,622
Interest checking	40	30
Savings products	488	478
Time deposits	3,373	2,278
Total deposits	5,895	4,408
Total U.S. Bancorp shareholders' equity	$ 18,202	$ 16,421