Basis of Presentation - Line of Business Financial Performance (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Condensed Income Statement
Securities gains (losses), net	$ 5
Other intangibles	57	71
Total noninterest expense	2,470	2,560
Provision for credit losses	403	481
Net income	1,387	1,305
Net (income) loss attributable to noncontrolling interests	41	33
Net income attributable to U.S. Bancorp	1,428	1,338
Wholesale Banking and Commercial Real Estate [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	511	535
Net interest income (taxable-equivalent basis), Percent change	(4.50%)
Noninterest income	278	311
Noninterest income, Percent change	(10.60%)
Securities gains (losses), net	0
Securities gains (losses), net, Percent change	0.00%
Total net revenue	789	846
Total net revenue, Percent change	(6.70%)
Noninterest expense	318	319
Noninterest expense, Percent change	(0.30%)
Other intangibles	2	4
Other intangibles, Percent change	(50.00%)
Total noninterest expense	320	323
Total noninterest expense, Percent change	(0.90%)
Income before provision and income taxes	469	523
Income before provision and income taxes, Percent change	(10.30%)
Provision for credit losses	(53)	3
Income before income taxes	522	520
Income before income taxes, Percent change	0.40%
Income taxes and taxable-equivalent adjustment	190	189
Income taxes and taxable-equivalent adjustment, Percent change	0.50%
Net income	332	331
Net income, Percent change	0.30%
Net (income) loss attributable to noncontrolling interests	0
Net (income) loss attributable to noncontrolling interests, Percent change	0.00%
Net income attributable to U.S. Bancorp	332	331
Net income attributable to U.S. Bancorp, Percent change	0.30%
Average Balance Sheet
Commercial	49,221	42,253
Commercial, Percent change	16.50%
Commercial real estate	19,901	19,422
Commercial real estate, Percent change	2.50%
Residential mortgages	30	64
Residential mortgages, Percent change	(53.10%)
Credit card	0
Credit card, Percent change	0.00%
Other retail	13	4
Total loans, excluding covered loans	69,165	61,743
Total loans, excluding covered loans, Percent change	12.00%
Covered loans	460	1,129
Covered loans, Percent change	(59.30%)
Total loans	69,625	62,872
Total loans, Percent change	10.70%
Goodwill	1,604	1,604
Goodwill, Percent change	0.00%
Other intangible assets	27	42
Other intangible assets, Percent change	(35.70%)
Assets	75,703	68,438
Assets, Percent change	10.60%
Noninterest-bearing deposits	29,878	30,371
Noninterest-bearing deposits, Percent change	(1.60%)
Interest checking	10,893	13,104
Interest checking, Percent change	(16.90%)
Savings products	11,858	8,885
Savings products, Percent change	33.50%
Time deposits	16,715	13,353
Time deposits, Percent change	25.20%
Total deposits	69,344	65,713
Total deposits, Percent change	5.50%
Total U.S. Bancorp shareholders' equity	7,211	6,264
Total U.S. Bancorp shareholders' equity, Percent change	15.10%
Consumer and Small Business Banking [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	1,151	1,181
Net interest income (taxable-equivalent basis), Percent change	(2.50%)
Noninterest income	783	865
Noninterest income, Percent change	(9.50%)
Securities gains (losses), net	0
Securities gains (losses), net, Percent change	0.00%
Total net revenue	1,934	2,046
Total net revenue, Percent change	(5.50%)
Noninterest expense	1,201	1,181
Noninterest expense, Percent change	1.70%
Other intangibles	11	13
Other intangibles, Percent change	(15.40%)
Total noninterest expense	1,212	1,194
Total noninterest expense, Percent change	1.50%
Income before provision and income taxes	722	852
Income before provision and income taxes, Percent change	(15.30%)
Provision for credit losses	244	255
Provision for credit losses, Percent change	(4.30%)
Income before income taxes	478	597
Income before income taxes, Percent change	(19.90%)
Income taxes and taxable-equivalent adjustment	174	217
Income taxes and taxable-equivalent adjustment, Percent change	(19.80%)
Net income	304	380
Net income, Percent change	(20.00%)
Net (income) loss attributable to noncontrolling interests	0
Net (income) loss attributable to noncontrolling interests, Percent change	0.00%
Net income attributable to U.S. Bancorp	304	380
Net income attributable to U.S. Bancorp, Percent change	(20.00%)
Average Balance Sheet
Commercial	8,313	7,896
Commercial, Percent change	5.30%
Commercial real estate	16,566	15,911
Commercial real estate, Percent change	4.10%
Residential mortgages	44,498	37,378
Residential mortgages, Percent change	19.00%
Credit card	0
Credit card, Percent change	0.00%
Other retail	44,917	45,581
Other retail, Percent change	(1.50%)
Total loans, excluding covered loans	114,294	106,766
Total loans, excluding covered loans, Percent change	7.10%
Covered loans	6,941	7,893
Covered loans, Percent change	(12.10%)
Total loans	121,235	114,659
Total loans, Percent change	5.70%
Goodwill	3,515	3,515
Goodwill, Percent change	0.00%
Other intangible assets	2,014	1,765
Other intangible assets, Percent change	14.10%
Assets	139,259	130,711
Assets, Percent change	6.50%
Noninterest-bearing deposits	21,392	18,745
Noninterest-bearing deposits, Percent change	14.10%
Interest checking	32,412	28,998
Interest checking, Percent change	11.80%
Savings products	45,653	42,360
Savings products, Percent change	7.80%
Time deposits	22,493	24,373
Time deposits, Percent change	(7.70%)
Total deposits	121,950	114,476
Total deposits, Percent change	6.50%
Total U.S. Bancorp shareholders' equity	11,988	10,769
Total U.S. Bancorp shareholders' equity, Percent change	11.30%
Wealth Management and Securities Services [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	92	94
Net interest income (taxable-equivalent basis), Percent change	(2.10%)
Noninterest income	294	267
Noninterest income, Percent change	10.10%
Total net revenue	386	361
Total net revenue, Percent change	6.90%
Noninterest expense	322	281
Noninterest expense, Percent change	14.60%
Other intangibles	9	10
Other intangibles, Percent change	(10.00%)
Total noninterest expense	331	291
Total noninterest expense, Percent change	13.70%
Income before provision and income taxes	55	70
Income before provision and income taxes, Percent change	(21.40%)
Provision for credit losses		(1)
Income before income taxes	55	71
Income before income taxes, Percent change	(22.50%)
Income taxes and taxable-equivalent adjustment	20	26
Income taxes and taxable-equivalent adjustment, Percent change	(23.10%)
Net income	35	45
Net income, Percent change	(22.20%)
Net income attributable to U.S. Bancorp	35	45
Net income attributable to U.S. Bancorp, Percent change	(22.20%)
Average Balance Sheet
Commercial	1,741	1,156
Commercial, Percent change	50.60%
Commercial real estate	640	575
Commercial real estate, Percent change	11.30%
Residential mortgages	580	382
Residential mortgages, Percent change	51.80%
Other retail	1,553	1,508
Other retail, Percent change	3.00%
Total loans, excluding covered loans	4,514	3,621
Total loans, excluding covered loans, Percent change	24.70%
Covered loans	9	12
Covered loans, Percent change	(25.00%)
Total loans	4,523	3,633
Total loans, Percent change	24.50%
Goodwill	1,528	1,467
Goodwill, Percent change	4.20%
Other intangible assets	182	176
Other intangible assets, Percent change	3.40%
Assets	7,394	6,242
Assets, Percent change	18.50%
Noninterest-bearing deposits	14,095	13,359
Noninterest-bearing deposits, Percent change	5.50%
Interest checking	4,668	4,050
Interest checking, Percent change	15.30%
Savings products	26,851	23,365
Savings products, Percent change	14.90%
Time deposits	5,946	4,542
Time deposits, Percent change	30.90%
Total deposits	51,560	45,316
Total deposits, Percent change	13.80%
Total U.S. Bancorp shareholders' equity	2,361	2,204
Total U.S. Bancorp shareholders' equity, Percent change	7.10%
Payment Services [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	388	396
Net interest income (taxable-equivalent basis), Percent change	(2.00%)
Noninterest income	747	732
Noninterest income, Percent change	2.00%
Total net revenue	1,135	1,128
Total net revenue, Percent change	0.60%
Noninterest expense	481	454
Noninterest expense, Percent change	5.90%
Other intangibles	35	44
Other intangibles, Percent change	(20.50%)
Total noninterest expense	516	498
Total noninterest expense, Percent change	3.60%
Income before provision and income taxes	619	630
Income before provision and income taxes, Percent change	(1.70%)
Provision for credit losses	205	216
Provision for credit losses, Percent change	(5.10%)
Income before income taxes	414	414
Income taxes and taxable-equivalent adjustment	151	151
Net income	263	263
Net (income) loss attributable to noncontrolling interests	(9)	(10)
Net (income) loss attributable to noncontrolling interests, Percent change	10.00%
Net income attributable to U.S. Bancorp	254	253
Net income attributable to U.S. Bancorp, Percent change	0.40%
Average Balance Sheet
Commercial	5,860	5,647
Commercial, Percent change	3.80%
Credit card	16,528	16,778
Credit card, Percent change	(1.50%)
Other retail	763	837
Other retail, Percent change	(8.80%)
Total loans, excluding covered loans	23,151	23,262
Total loans, excluding covered loans, Percent change	(0.50%)
Covered loans	5	5
Total loans	23,156	23,267
Total loans, Percent change	(0.50%)
Goodwill	2,508	2,350
Goodwill, Percent change	6.70%
Other intangible assets	612	771
Other intangible assets, Percent change	(20.60%)
Assets	29,444	29,752
Assets, Percent change	(1.00%)
Noninterest-bearing deposits	692	660
Noninterest-bearing deposits, Percent change	4.80%
Interest checking	430	1,305
Interest checking, Percent change	(67.00%)
Savings products	47	34
Savings products, Percent change	38.20%
Total deposits	1,169	1,999
Total deposits, Percent change	(41.50%)
Total U.S. Bancorp shareholders' equity	5,949	5,729
Total U.S. Bancorp shareholders' equity, Percent change	3.80%
Treasury and Corporate Support [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	567	484
Net interest income (taxable-equivalent basis), Percent change	17.10%
Noninterest income	58	64
Noninterest income, Percent change	(9.40%)
Securities gains (losses), net	5
Total net revenue	630	548
Total net revenue, Percent change	15.00%
Noninterest expense	91	254
Noninterest expense, Percent change	(64.20%)
Total noninterest expense	91	254
Total noninterest expense, Percent change	(64.20%)
Income before provision and income taxes	539	294
Income before provision and income taxes, Percent change	83.30%
Provision for credit losses	7	8
Provision for credit losses, Percent change	(12.50%)
Income before income taxes	532	286
Income before income taxes, Percent change	86.00%
Income taxes and taxable-equivalent adjustment	79
Net income	453	286
Net income, Percent change	58.40%
Net (income) loss attributable to noncontrolling interests	50	43
Net (income) loss attributable to noncontrolling interests, Percent change	16.30%
Net income attributable to U.S. Bancorp	503	329
Net income attributable to U.S. Bancorp, Percent change	52.90%
Average Balance Sheet
Commercial	164	179
Commercial, Percent change	(8.40%)
Commercial real estate	111	77
Commercial real estate, Percent change	44.20%
Residential mortgages	1	7
Residential mortgages, Percent change	(85.70%)
Total loans, excluding covered loans	276	263
Total loans, excluding covered loans, Percent change	4.90%
Covered loans	3,606	5,467
Covered loans, Percent change	(34.00%)
Total loans	3,882	5,730
Total loans, Percent change	(32.30%)
Other intangible assets	3	4
Other intangible assets, Percent change	(25.00%)
Assets	99,587	101,144
Assets, Percent change	(1.50%)
Noninterest-bearing deposits	343	448
Noninterest-bearing deposits, Percent change	(23.40%)
Interest checking	1	1
Savings products	96	129
Savings products, Percent change	(25.60%)
Time deposits	555	202
Total deposits	995	780
Total deposits, Percent change	27.60%
Total U.S. Bancorp shareholders' equity	11,668	10,449
Total U.S. Bancorp shareholders' equity, Percent change	11.70%
Consolidated Company [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	2,709	2,690
Net interest income (taxable-equivalent basis), Percent change	0.70%
Noninterest income	2,160	2,239
Noninterest income, Percent change	(3.50%)
Securities gains (losses), net	5
Total net revenue	4,874	4,929
Total net revenue, Percent change	(1.10%)
Noninterest expense	2,413	2,489
Noninterest expense, Percent change	(3.10%)
Other intangibles	57	71
Other intangibles, Percent change	(19.70%)
Total noninterest expense	2,470	2,560
Total noninterest expense, Percent change	(3.50%)
Income before provision and income taxes	2,404	2,369
Income before provision and income taxes, Percent change	1.50%
Provision for credit losses	403	481
Provision for credit losses, Percent change	(16.20%)
Income before income taxes	2,001	1,888
Income before income taxes, Percent change	6.00%
Income taxes and taxable-equivalent adjustment	614	583
Income taxes and taxable-equivalent adjustment, Percent change	5.30%
Net income	1,387	1,305
Net income, Percent change	6.30%
Net (income) loss attributable to noncontrolling interests	41	33
Net (income) loss attributable to noncontrolling interests, Percent change	24.20%
Net income attributable to U.S. Bancorp	1,428	1,338
Net income attributable to U.S. Bancorp, Percent change	6.70%
Average Balance Sheet
Commercial	65,299	57,131
Commercial, Percent change	14.30%
Commercial real estate	37,218	35,985
Commercial real estate, Percent change	3.40%
Residential mortgages	45,109	37,831
Residential mortgages, Percent change	19.20%
Credit card	16,528	16,778
Credit card, Percent change	(1.50%)
Other retail	47,246	47,930
Other retail, Percent change	(1.40%)
Total loans, excluding covered loans	211,400	195,655
Total loans, excluding covered loans, Percent change	8.00%
Covered loans	11,021	14,506
Covered loans, Percent change	(24.00%)
Total loans	222,421	210,161
Total loans, Percent change	5.80%
Goodwill	9,155	8,936
Goodwill, Percent change	2.50%
Other intangible assets	2,838	2,758
Other intangible assets, Percent change	2.90%
Assets	351,387	336,287
Assets, Percent change	4.50%
Noninterest-bearing deposits	66,400	63,583
Noninterest-bearing deposits, Percent change	4.40%
Interest checking	48,404	47,458
Interest checking, Percent change	2.00%
Savings products	84,505	74,773
Savings products, Percent change	13.00%
Time deposits	45,709	42,470
Time deposits, Percent change	7.60%
Total deposits	245,018	228,284
Total deposits, Percent change	7.30%
Total U.S. Bancorp shareholders' equity	$ 39,177	$ 35,415
Total U.S. Bancorp shareholders' equity, Percent change	10.60%