Basis of Presentation - Line of Business Financial Performance (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 2,943	$ 2,821	$ 8,727	$ 8,343
Net interest income (taxable-equivalent basis), Percent change	4.30%		4.60%
Noninterest income	$ 2,435	2,327	$ 7,130	6,753
Noninterest income, Percent change	4.60%		5.60%
Securities gains (losses), net	$ 10	(1)	$ 16	(1)
Securities gains (losses), net, Percent change	0.00%		0.00%
Total net revenue	$ 5,388	5,147	$ 15,873	15,095
Total net revenue, Percent change	4.70%		5.20%
Noninterest expense, Percent change	5.60%		6.80%
Other intangibles, Percent change	7.10%		4.70%
Total noninterest expense, Percent change	5.60%		6.80%
Income before provision and income taxes, Percent change	3.60%		3.30%
Provision for credit losses, Percent change	15.20%		18.70%
Income before income taxes, Percent change	2.00%		1.20%
Income taxes and taxable-equivalent adjustment, Percent change	4.90%		3.80%
Net income, Percent change	0.90%		0.20%
Net (income) loss attributable to noncontrolling interests, Percent change			(4.90%)
Net income attributable to U.S. Bancorp, Percent change	0.90%		0.20%
Noninterest expense	$ 2,886	2,733	$ 8,538	7,994
Other intangibles	45	42	134	128
Total noninterest expense	2,931	2,775	8,672	8,122
Income before provision and income taxes	2,457	2,372	7,201	6,973
Provision for credit losses	325	282	982	827
Income before income taxes	2,132	2,090	6,219	6,146
Income taxes and taxable-equivalent adjustment	616	587	1,766	1,702
Net income	1,516	1,503	4,453	4,444
Net (income) loss attributable to noncontrolling interests	(14)	(14)	(43)	(41)
Net income attributable to U.S. Bancorp	1,502	1,489	4,410	4,403
Average Balance Sheet
Commercial	$ 92,369	84,704	$ 91,451	83,167
Commercial, Percent change	9.00%		10.00%
Commercial real estate	$ 43,374	42,316	$ 42,922	42,476
Commercial real estate, Percent change	2.50%		1.10%
Residential mortgages	$ 56,284	51,831	$ 55,334	51,458
Residential mortgages, Percent change	8.60%		7.50%
Credit card	$ 20,628	17,944	$ 20,339	17,794
Credit card, Percent change	15.00%		14.30%
Other retail	$ 52,851	48,849	$ 51,809	48,411
Other retail, Percent change	8.20%		7.00%
Total loans, excluding covered loans	$ 265,506	245,644	$ 261,855	243,306
Total loans, excluding covered loans, Percent change	8.10%		7.60%
Covered loans	$ 4,131	4,892	$ 4,324	5,052
Covered loans, Percent change	(15.60%)		(14.40%)
Total loans	$ 269,637	250,536	$ 266,179	248,358
Total loans, Percent change	7.60%		7.20%
Goodwill, Percent change	(0.10%)		(0.10%)
Other intangible assets, Percent change	(9.60%)		(3.50%)
Assets, Percent change	6.70%		5.60%
Noninterest-bearing deposits, Percent change	1.30%		3.00%
Interest checking, Percent change	11.50%		9.30%
Savings products, Percent change	19.40%		15.90%
Time deposits, Percent change	(4.70%)		(8.40%)
Total deposits, Percent change	10.00%		8.00%
Total U.S. Bancorp shareholders' equity, Percent change	6.50%		6.20%
Goodwill	$ 9,358	9,371	$ 9,361	9,372
Other intangible assets	2,879	3,185	3,017	3,127
Assets	437,863	410,439	429,421	406,757
Noninterest-bearing deposits	82,021	80,940	79,928	77,623
Interest checking	63,456	56,888	60,746	55,592
Savings products	140,616	117,818	133,191	114,931
Time deposits	32,455	34,046	33,447	36,527
Total deposits	318,548	289,692	307,312	284,673
Total U.S. Bancorp shareholders' equity	47,791	44,867	47,240	44,489
Wholesale Banking and Commercial Real Estate [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 563	507	$ 1,638	1,495
Net interest income (taxable-equivalent basis), Percent change	11.00%		9.60%
Noninterest income	$ 220	225	$ 676	670
Noninterest income, Percent change	(2.20%)		0.90%
Securities gains (losses), net, Percent change	0.00%		0.00%
Total net revenue	$ 783	732	$ 2,314	2,165
Total net revenue, Percent change	7.00%		6.90%
Noninterest expense, Percent change	5.80%		6.20%
Total noninterest expense, Percent change	5.80%		6.20%
Income before provision and income taxes, Percent change	8.00%		7.50%
Provision for credit losses, Percent change	(8.80%)
Income before income taxes, Percent change	12.10%		(11.90%)
Income taxes and taxable-equivalent adjustment, Percent change	12.00%		(12.10%)
Net income, Percent change	12.20%		(11.70%)
Net income attributable to U.S. Bancorp, Percent change	12.20%		(11.70%)
Noninterest expense	$ 348	329	$ 1,047	986
Other intangibles	1	1	3	3
Total noninterest expense	349	330	1,050	989
Income before provision and income taxes	434	402	1,264	1,176
Provision for credit losses	73	80	342	130
Income before income taxes	361	322	922	1,046
Income taxes and taxable-equivalent adjustment	131	117	335	381
Net income	230	205	587	665
Net income attributable to U.S. Bancorp	230	205	587	665
Average Balance Sheet
Commercial	$ 70,813	64,984	$ 70,412	63,828
Commercial, Percent change	9.00%		10.30%
Commercial real estate	$ 21,476	20,587	$ 21,099	20,519
Commercial real estate, Percent change	4.30%		2.80%
Residential mortgages	$ 8	8	$ 7	8
Residential mortgages, Percent change			(12.50%)
Other retail	2	2	$ 2	3
Other retail, Percent change			(33.30%)
Total loans, excluding covered loans	$ 92,299	85,581	$ 91,520	84,358
Total loans, excluding covered loans, Percent change	7.80%		8.50%
Total loans	$ 92,299	85,581	$ 91,520	84,358
Total loans, Percent change	7.80%		8.50%
Other intangible assets, Percent change	(20.00%)		(19.00%)
Assets, Percent change	7.70%		7.70%
Noninterest-bearing deposits, Percent change	(0.80%)		2.10%
Interest checking, Percent change	27.90%		8.40%
Savings products, Percent change	53.50%		47.20%
Time deposits, Percent change	(2.40%)		(16.00%)
Total deposits, Percent change	19.40%		13.70%
Total U.S. Bancorp shareholders' equity, Percent change	5.90%		8.10%
Goodwill	$ 1,647	1,647	$ 1,647	1,647
Other intangible assets	16	20	17	21
Assets	100,871	93,681	99,937	92,805
Noninterest-bearing deposits	36,624	36,929	36,498	35,742
Interest checking	9,628	7,528	8,202	7,563
Savings products	44,288	28,855	40,028	27,194
Time deposits	13,490	13,827	13,000	15,467
Total deposits	104,030	87,139	97,728	85,966
Total U.S. Bancorp shareholders' equity	8,997	8,497	8,927	8,261
Consumer and Small Business Banking [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 1,203	1,150	$ 3,532	3,410
Net interest income (taxable-equivalent basis), Percent change	4.60%		3.60%
Noninterest income	$ 712	629	$ 1,900	1,877
Noninterest income, Percent change	13.20%		1.20%
Securities gains (losses), net, Percent change	0.00%		0.00%
Total net revenue	$ 1,915	1,779	$ 5,432	5,287
Total net revenue, Percent change	7.60%		2.70%
Noninterest expense, Percent change	2.20%		2.40%
Other intangibles, Percent change	(20.00%)		(20.00%)
Total noninterest expense, Percent change	2.10%		2.20%
Income before provision and income taxes, Percent change	21.10%		3.80%
Provision for credit losses, Percent change	45.20%		(81.40%)
Income before income taxes, Percent change	19.60%		10.40%
Income taxes and taxable-equivalent adjustment, Percent change	19.60%		10.60%
Net income, Percent change	19.60%		10.30%
Net income attributable to U.S. Bancorp, Percent change	19.60%		10.30%
Noninterest expense	$ 1,275	1,247	$ 3,704	3,616
Other intangibles	8	10	24	30
Total noninterest expense	1,283	1,257	3,728	3,646
Income before provision and income taxes	632	522	1,704	1,641
Provision for credit losses	45	31	22	118
Income before income taxes	587	491	1,682	1,523
Income taxes and taxable-equivalent adjustment	214	179	613	554
Net income	373	312	1,069	969
Net income attributable to U.S. Bancorp	373	312	1,069	969
Average Balance Sheet
Commercial	$ 10,546	10,004	$ 10,367	9,839
Commercial, Percent change	5.40%		5.40%
Commercial real estate	$ 18,300	17,857	$ 18,143	17,902
Commercial real estate, Percent change	2.50%		1.30%
Residential mortgages	$ 53,933	49,924	$ 53,127	49,678
Residential mortgages, Percent change	8.00%		6.90%
Other retail	$ 50,785	46,717	$ 49,738	46,301
Other retail, Percent change	8.70%		7.40%
Total loans, excluding covered loans	$ 133,564	124,502	$ 131,375	123,720
Total loans, excluding covered loans, Percent change	7.30%		6.20%
Covered loans	$ 4,107	4,839	$ 4,289	5,006
Covered loans, Percent change	(15.10%)		(14.30%)
Total loans	$ 137,671	129,341	$ 135,664	128,726
Total loans, Percent change	6.40%		5.40%
Other intangible assets, Percent change	(14.70%)		(7.00%)
Assets, Percent change	4.20%		3.10%
Noninterest-bearing deposits, Percent change	7.00%		6.20%
Interest checking, Percent change	9.60%		8.80%
Savings products, Percent change	6.70%		6.90%
Time deposits, Percent change	(7.50%)		(10.80%)
Total deposits, Percent change	6.00%		5.20%
Total U.S. Bancorp shareholders' equity, Percent change	6.40%		1.80%
Goodwill	$ 3,681	3,681	$ 3,681	3,681
Other intangible assets	2,270	2,661	2,393	2,573
Assets	153,496	147,273	150,704	146,200
Noninterest-bearing deposits	28,380	26,514	27,111	25,539
Interest checking	43,827	40,005	43,175	39,672
Savings products	57,777	54,161	57,057	53,381
Time deposits	14,280	15,439	14,392	16,130
Total deposits	144,264	136,119	141,735	134,722
Total U.S. Bancorp shareholders' equity	11,312	10,629	11,138	10,944
Wealth Management and Securities Services [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 135	90	$ 374	252
Net interest income (taxable-equivalent basis), Percent change	50.00%		48.40%
Noninterest income	$ 403	368	$ 1,183	1,100
Noninterest income, Percent change	9.50%		7.50%
Securities gains (losses), net, Percent change	0.00%		0.00%
Total net revenue	$ 538	458	$ 1,557	1,352
Total net revenue, Percent change	17.50%		15.20%
Noninterest expense, Percent change	7.90%		5.10%
Other intangibles, Percent change	(14.30%)		(14.30%)
Total noninterest expense, Percent change	7.50%		4.70%
Income before provision and income taxes, Percent change	55.20%		56.00%
Income before income taxes, Percent change	57.90%		56.70%
Income taxes and taxable-equivalent adjustment, Percent change	57.10%		57.00%
Net income, Percent change	58.30%		56.60%
Net income attributable to U.S. Bancorp, Percent change	58.30%		56.60%
Noninterest expense	$ 383	355	$ 1,110	1,056
Other intangibles	6	7	18	21
Total noninterest expense	389	362	1,128	1,077
Income before provision and income taxes	149	96	429	275
Provision for credit losses	(1)	1	(2)
Income before income taxes	150	95	431	275
Income taxes and taxable-equivalent adjustment	55	35	157	100
Net income	95	60	274	175
Net income attributable to U.S. Bancorp	95	60	274	175
Average Balance Sheet
Commercial	$ 2,892	2,212	$ 2,874	2,254
Commercial, Percent change	30.70%		27.50%
Commercial real estate	$ 513	570	$ 521	569
Commercial real estate, Percent change	(10.00%)		(8.40%)
Residential mortgages	$ 2,343	1,887	$ 2,200	1,760
Residential mortgages, Percent change	24.20%		25.00%
Other retail	$ 1,549	1,544	$ 1,537	1,502
Other retail, Percent change	0.30%		2.30%
Total loans, excluding covered loans	$ 7,297	6,213	$ 7,132	6,085
Total loans, excluding covered loans, Percent change	17.40%		17.20%
Covered loans		1		1
Total loans	$ 7,297	6,214	$ 7,132	6,086
Total loans, Percent change	17.40%		17.20%
Goodwill, Percent change			(0.10%)
Other intangible assets, Percent change	(19.50%)		(20.00%)
Assets, Percent change	13.90%		12.10%
Noninterest-bearing deposits, Percent change	(7.40%)		(3.70%)
Interest checking, Percent change	14.50%		20.80%
Savings products, Percent change	10.90%		5.10%
Time deposits, Percent change	0.10%		9.30%
Total deposits, Percent change	6.30%		5.40%
Total U.S. Bancorp shareholders' equity, Percent change	3.00%		3.20%
Goodwill	$ 1,567	1,567	$ 1,566	1,567
Other intangible assets	99	123	104	130
Assets	10,382	9,117	10,249	9,143
Noninterest-bearing deposits	13,825	14,922	13,270	13,776
Interest checking	9,967	8,703	9,328	7,721
Savings products	37,961	34,227	35,515	33,785
Time deposits	3,777	3,775	3,743	3,426
Total deposits	65,530	61,627	61,856	58,708
Total U.S. Bancorp shareholders' equity	2,378	2,308	2,379	2,306
Payment Services [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 538	484	$ 1,578	1,410
Net interest income (taxable-equivalent basis), Percent change	11.20%		11.90%
Noninterest income	$ 912	874	$ 2,651	2,501
Noninterest income, Percent change	4.30%		6.00%
Securities gains (losses), net, Percent change	0.00%		0.00%
Total net revenue	$ 1,450	1,358	$ 4,229	3,911
Total net revenue, Percent change	6.80%		8.10%
Noninterest expense, Percent change	6.90%		5.20%
Other intangibles, Percent change	25.00%		20.30%
Total noninterest expense, Percent change	7.60%		5.80%
Income before provision and income taxes, Percent change	6.00%		10.50%
Provision for credit losses, Percent change	15.60%		5.10%
Income before income taxes, Percent change	2.70%		12.80%
Income taxes and taxable-equivalent adjustment, Percent change	2.60%		12.70%
Net income, Percent change	2.70%		12.80%
Net (income) loss attributable to noncontrolling interests, Percent change			(4.20%)
Net income attributable to U.S. Bancorp, Percent change	2.80%		13.10%
Noninterest expense	$ 679	635	$ 1,991	1,892
Other intangibles	30	24	89	74
Total noninterest expense	709	659	2,080	1,966
Income before provision and income taxes	741	699	2,149	1,945
Provision for credit losses	208	180	615	585
Income before income taxes	533	519	1,534	1,360
Income taxes and taxable-equivalent adjustment	194	189	558	495
Net income	339	330	976	865
Net (income) loss attributable to noncontrolling interests	(8)	(8)	(25)	(24)
Net income attributable to U.S. Bancorp	331	322	951	841
Average Balance Sheet
Commercial	$ 7,766	7,239	$ 7,438	6,975
Commercial, Percent change	7.30%		6.60%
Credit card	$ 20,628	17,944	$ 20,339	17,794
Credit card, Percent change	15.00%		14.30%
Other retail	$ 515	586	$ 532	605
Other retail, Percent change	(12.10%)		(12.10%)
Total loans, excluding covered loans	$ 28,909	25,769	$ 28,309	25,374
Total loans, excluding covered loans, Percent change	12.20%		11.60%
Total loans	$ 28,909	25,769	$ 28,309	25,374
Total loans, Percent change	12.20%		11.60%
Goodwill, Percent change	(0.50%)		(0.40%)
Other intangible assets, Percent change	29.70%		24.80%
Assets, Percent change	10.00%		9.20%
Noninterest-bearing deposits, Percent change	12.10%		8.20%
Savings products, Percent change	6.50%		7.80%
Total deposits, Percent change	(32.60%)		(33.40%)
Total U.S. Bancorp shareholders' equity, Percent change	9.60%		9.50%
Goodwill	$ 2,463	2,476	$ 2,467	2,477
Other intangible assets	494	381	503	403
Assets	34,733	31,585	34,245	31,364
Noninterest-bearing deposits	954	851	947	875
Interest checking		618		602
Savings products	98	92	97	90
Total deposits	1,052	1,561	1,044	1,567
Total U.S. Bancorp shareholders' equity	6,386	5,829	6,362	5,809
Treasury and Corporate Support [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 504	590	$ 1,605	1,776
Net interest income (taxable-equivalent basis), Percent change	(14.60%)		(9.60%)
Noninterest income	$ 188	231	$ 720	605
Noninterest income, Percent change	(18.60%)		19.00%
Securities gains (losses), net	$ 10	(1)	$ 16	(1)
Securities gains (losses), net, Percent change	0.00%		0.00%
Total net revenue	$ 702	820	$ 2,341	2,380
Total net revenue, Percent change	(14.40%)		(1.60%)
Noninterest expense, Percent change	20.40%		54.50%
Total noninterest expense, Percent change	20.40%		54.50%
Income before provision and income taxes, Percent change	(23.30%)		(14.50%)
Income before income taxes, Percent change	(24.40%)		(15.00%)
Income taxes and taxable-equivalent adjustment, Percent change	(67.20%)		(40.10%)
Net income, Percent change	(19.60%)		(12.60%)
Net (income) loss attributable to noncontrolling interests, Percent change			(5.90%)
Net income attributable to U.S. Bancorp, Percent change	(19.80%)		(12.80%)
Noninterest expense	$ 201	167	$ 686	444
Total noninterest expense	201	167	686	444
Income before provision and income taxes	501	653	1,655	1,936
Provision for credit losses		(10)	5	(6)
Income before income taxes	501	663	1,650	1,942
Income taxes and taxable-equivalent adjustment	22	67	103	172
Net income	479	596	1,547	1,770
Net (income) loss attributable to noncontrolling interests	(6)	(6)	(18)	(17)
Net income attributable to U.S. Bancorp	473	590	1,529	1,753
Average Balance Sheet
Commercial	$ 352	265	$ 360	271
Commercial, Percent change	32.80%		32.80%
Commercial real estate	$ 3,085	3,302	$ 3,159	3,486
Commercial real estate, Percent change	(6.60%)		(9.40%)
Residential mortgages		12		12
Total loans, excluding covered loans	$ 3,437	3,579	$ 3,519	3,769
Total loans, excluding covered loans, Percent change	(4.00%)		(6.60%)
Covered loans	$ 24	52	$ 35	45
Covered loans, Percent change	(53.80%)		(22.20%)
Total loans	$ 3,461	3,631	$ 3,554	3,814
Total loans, Percent change	(4.70%)		(6.80%)
Assets, Percent change	7.50%		5.50%
Noninterest-bearing deposits, Percent change	29.80%		24.30%
Interest checking, Percent change			20.60%
Savings products, Percent change	1.90%		2.70%
Time deposits, Percent change	(9.70%)		53.70%
Total deposits, Percent change	13.10%		33.40%
Total U.S. Bancorp shareholders' equity, Percent change	6.30%		7.40%
Assets	$ 138,381	128,783	$ 134,286	127,245
Noninterest-bearing deposits	2,238	1,724	2,102	1,691
Interest checking	34	34	41	34
Savings products	492	483	494	481
Time deposits	908	1,005	2,312	1,504
Total deposits	3,672	3,246	4,949	3,710
Total U.S. Bancorp shareholders' equity	$ 18,718	$ 17,604	$ 18,434	$ 17,169