Basis of Presentation - Line of Business Financial Performance (Detail) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Condensed Income Statement
Net interest income (taxable-equivalent basis)		$ 3,332	$ 3,226	$ 6,618	$ 6,423
Net interest income (taxable-equivalent basis), Percent change		3.30%		3.00%
Noninterest income	[1]	$ 2,473	2,404	$ 4,759	4,671
Noninterest income, Percent change		2.90%		1.90%
Securities gains (losses), net		$ 17	10	$ 22	15
Securities gains (losses), net, Percent change		70.00%		46.70%
Total net revenue		$ 5,822	5,640	$ 11,399	11,109
Total net revenue, Percent change		3.20%		2.60%
Noninterest expense, Percent change		2.20%		1.60%
Other intangibles, Percent change		5.00%		3.80%
Total noninterest expense, Percent change		2.20%		1.60%
Income before provision and income taxes, Percent change		4.50%		3.80%
Provision for credit losses, Percent change		11.60%		11.10%
Income before income taxes, Percent change		3.40%		2.70%
Income taxes and taxable-equivalent adjustment, Percent change		1.30%		2.30%
Net income, Percent change		4.00%		2.80%
Net (income) loss attributable to noncontrolling interests, Percent change		12.50%		(6.70%)
Net income attributable to U.S. Bancorp, Percent change		4.10%		2.80%
Noninterest expense		$ 3,111	3,045	$ 6,158	6,061
Other intangibles		42	40	82	79
Total noninterest expense		3,153	3,085	6,240	6,140
Income before provision and income taxes		2,669	2,555	5,159	4,969
Provision for credit losses		365	327	742	668
Income before income taxes		2,304	2,228	4,417	4,301
Income taxes and taxable-equivalent adjustment		476	470	881	861
Net income		1,828	1,758	3,536	3,440
Net (income) loss attributable to noncontrolling interests		(7)	(8)	(16)	(15)
Net income attributable to U.S. Bancorp		1,821	1,750	3,520	3,425
Average Balance Sheet
Commercial		$ 103,233	98,353	$ 102,600	97,912
Commercial, Percent change		5.00%		4.80%
Commercial real estate		$ 39,365	39,857	$ 39,417	40,110
Commercial real estate, Percent change		(1.20%)		(1.70%)
Residential mortgages		$ 66,834	60,834	$ 66,212	60,505
Residential mortgages, Percent change		9.90%		9.40%
Credit card		$ 22,830	21,220	$ 22,714	21,252
Credit card, Percent change		7.60%		6.90%
Other retail		$ 56,956	55,463	$ 56,729	56,253
Other retail, Percent change		2.70%		0.80%
Total loans, excluding covered loans			2,897		2,972
Total loans		$ 289,218	278,624	$ 287,672	279,004
Total loans, Percent change		3.80%		3.10%
Goodwill, Percent change		1.20%		1.20%
Other intangible assets, Percent change		(2.70%)		0.20%
Assets, Percent change		3.80%		2.90%
Noninterest-bearing deposits, Percent change		(7.50%)		(7.50%)
Interest checking, Percent change		0.70%		1.70%
Savings products, Percent change		4.20%		1.10%
Time deposits, Percent change		25.50%		23.80%
Total deposits, Percent change		3.10%		1.70%
Total U.S. Bancorp shareholders' equity, Percent change		6.30%		6.00%
Goodwill		$ 9,545	9,433	$ 9,549	9,436
Other intangible assets		3,309	3,401	3,383	3,375
Assets		471,598	454,489	467,521	454,389
Noninterest-bearing deposits		73,096	78,987	73,263	79,234
Interest checking		70,433	69,918	71,301	70,136
Savings products		154,621	148,402	149,662	148,080
Time deposits		47,082	37,515	46,100	37,252
Total deposits		345,232	334,822	340,326	334,702
Total U.S. Bancorp shareholders' equity		52,438	49,322	52,016	49,075
Corporate and Commercial Banking [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)		$ 718	726	$ 1,444	1,448
Net interest income (taxable-equivalent basis), Percent change		(1.10%)		(0.30%)
Noninterest income		$ 245	223	$ 454	430
Noninterest income, Percent change		9.90%		5.60%
Total net revenue		$ 963	949	$ 1,898	1,878
Total net revenue, Percent change		1.50%		1.10%
Noninterest expense, Percent change		1.00%		2.10%
Total noninterest expense, Percent change		1.00%		2.10%
Income before provision and income taxes, Percent change		1.80%		0.30%
Provision for credit losses, Percent change		83.30%
Income before income taxes, Percent change				1.70%
Income taxes and taxable-equivalent adjustment, Percent change				1.50%
Net income, Percent change				1.70%
Net income attributable to U.S. Bancorp, Percent change				1.70%
Noninterest expense		$ 409	405	$ 818	801
Other intangibles		1	1	2	2
Total noninterest expense		410	406	820	803
Income before provision and income taxes		553	543	1,078	1,075
Provision for credit losses		(2)	(12)	(13)	2
Income before income taxes		555	555	1,091	1,073
Income taxes and taxable-equivalent adjustment		139	139	273	269
Net income		416	416	818	804
Net income attributable to U.S. Bancorp		416	416	818	804
Average Balance Sheet
Commercial		$ 78,067	74,757	$ 77,914	74,757
Commercial, Percent change		4.40%		4.20%
Commercial real estate		$ 18,514	18,690	$ 18,579	18,908
Commercial real estate, Percent change		(0.90%)		(1.70%)
Residential mortgages		$ 6	6	$ 6	6
Other retail		1	1	1	1
Total loans		$ 96,588	93,454	$ 96,500	93,672
Total loans, Percent change		3.40%		3.00%
Other intangible assets, Percent change		(18.20%)		(18.20%)
Assets, Percent change		4.10%		3.30%
Noninterest-bearing deposits, Percent change		(13.30%)		(12.90%)
Interest checking, Percent change		10.60%		17.10%
Savings products, Percent change		(0.30%)		(3.40%)
Time deposits, Percent change		(3.00%)		3.20%
Total deposits, Percent change		(4.00%)		(3.50%)
Total U.S. Bancorp shareholders' equity, Percent change		(1.30%)		(0.50%)
Goodwill		$ 1,647	1,647	$ 1,647	1,647
Other intangible assets		9	11	9	11
Assets		106,680	102,521	105,915	102,551
Noninterest-bearing deposits		28,874	33,314	29,424	33,779
Interest checking		10,552	9,544	11,150	9,518
Savings products		42,325	42,448	41,739	43,187
Time deposits		17,813	18,370	18,003	17,451
Total deposits		99,564	103,676	100,316	103,935
Total U.S. Bancorp shareholders' equity		10,362	10,498	10,400	10,457
Consumer and Business Banking [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)		$ 1,581	1,519	$ 3,148	3,031
Net interest income (taxable-equivalent basis), Percent change		4.10%		3.90%
Noninterest income		$ 567	594	$ 1,102	1,171
Noninterest income, Percent change		(4.50%)		(5.90%)
Total net revenue		$ 2,148	2,113	$ 4,250	4,202
Total net revenue, Percent change		1.70%		1.10%
Noninterest expense, Percent change		(0.70%)		(0.90%)
Other intangibles, Percent change		(28.60%)		(28.60%)
Total noninterest expense, Percent change		(0.80%)		(1.00%)
Income before provision and income taxes, Percent change		5.90%		4.80%
Provision for credit losses, Percent change		43.60%		35.50%
Income before income taxes, Percent change		3.00%		2.50%
Income taxes and taxable-equivalent adjustment, Percent change		3.30%		2.50%
Net income, Percent change		2.90%		2.50%
Net income attributable to U.S. Bancorp, Percent change		2.90%		2.50%
Noninterest expense		$ 1,318	1,327	$ 2,605	2,628
Other intangibles		5	7	10	14
Total noninterest expense		1,323	1,334	2,615	2,642
Income before provision and income taxes		825	779	1,635	1,560
Provision for credit losses		79	55	149	110
Income before income taxes		746	724	1,486	1,450
Income taxes and taxable-equivalent adjustment		187	181	372	363
Net income		559	543	1,114	1,087
Net income attributable to U.S. Bancorp		559	543	1,114	1,087
Average Balance Sheet
Commercial		$ 9,709	9,792	$ 9,581	9,722
Commercial, Percent change		(0.80%)		(1.50%)
Commercial real estate		$ 16,043	16,307	$ 16,024	16,363
Commercial real estate, Percent change		(1.60%)		(2.10%)
Residential mortgages		$ 63,073	57,578	$ 62,493	57,315
Residential mortgages, Percent change		9.50%		9.00%
Other retail		$ 54,889	53,330	$ 54,642	54,123
Other retail, Percent change		2.90%		1.00%
Covered loans			2,897		2,972
Total loans		$ 143,714	139,904	$ 142,740	140,495
Total loans, Percent change		2.70%		1.60%
Goodwill, Percent change		(4.30%)		(4.30%)
Other intangible assets, Percent change		(7.30%)		(3.50%)
Assets, Percent change		1.80%		0.70%
Noninterest-bearing deposits, Percent change		(1.10%)		(1.80%)
Interest checking, Percent change		1.70%		2.70%
Savings products, Percent change		0.20%		0.20%
Time deposits, Percent change		21.10%		19.40%
Total deposits, Percent change		2.20%		2.30%
Total U.S. Bancorp shareholders' equity, Percent change		(1.00%)		(0.90%)
Goodwill		$ 3,475	3,632	$ 3,475	3,632
Other intangible assets		2,717	2,932	2,799	2,902
Assets		157,384	154,579	156,039	154,999
Noninterest-bearing deposits		27,060	27,348	26,809	27,289
Interest checking		51,372	50,512	51,238	49,904
Savings products		62,041	61,936	61,709	61,608
Time deposits		15,470	12,773	15,135	12,673
Total deposits		155,943	152,569	154,891	151,474
Total U.S. Bancorp shareholders' equity		11,737	11,855	11,739	11,845
Wealth Management and Investment Services [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)		$ 299	282	$ 587	557
Net interest income (taxable-equivalent basis), Percent change		6.00%		5.40%
Noninterest income		$ 445	430	$ 875	861
Noninterest income, Percent change		3.50%		1.60%
Total net revenue		$ 744	712	$ 1,462	1,418
Total net revenue, Percent change		4.50%		3.10%
Noninterest expense, Percent change		(4.00%)		(1.00%)
Other intangibles, Percent change		(25.00%)		(25.00%)
Total noninterest expense, Percent change		(4.20%)		(1.20%)
Income before provision and income taxes, Percent change		20.00%		10.30%
Income before income taxes, Percent change		19.20%		10.70%
Income taxes and taxable-equivalent adjustment, Percent change		18.80%		10.50%
Net income, Percent change		19.40%		10.80%
Net income attributable to U.S. Bancorp, Percent change		19.40%		10.80%
Noninterest expense		$ 435	453	$ 868	877
Other intangibles		3	4	6	8
Total noninterest expense		438	457	874	885
Income before provision and income taxes		306	255	588	533
Provision for credit losses		2		(1)	1
Income before income taxes		304	255	589	532
Income taxes and taxable-equivalent adjustment		76	64	147	133
Net income		228	191	442	399
Net income attributable to U.S. Bancorp		228	191	442	399
Average Balance Sheet
Commercial		$ 3,952	3,737	$ 3,937	3,699
Commercial, Percent change		5.80%		6.40%
Commercial real estate		$ 494	522	$ 499	517
Commercial real estate, Percent change		(5.40%)		(3.50%)
Residential mortgages		$ 3,755	3,245	$ 3,713	3,179
Residential mortgages, Percent change		15.70%		16.80%
Other retail		$ 1,706	1,721	$ 1,718	1,710
Other retail, Percent change		(0.90%)		0.50%
Total loans		$ 9,907	9,225	$ 9,867	9,105
Total loans, Percent change		7.40%		8.40%
Goodwill, Percent change		(0.10%)		(0.10%)
Other intangible assets, Percent change		(24.20%)		(23.50%)
Assets, Percent change		7.70%		8.70%
Noninterest-bearing deposits, Percent change		(8.00%)		(7.70%)
Interest checking, Percent change		(15.30%)		(17.80%)
Savings products, Percent change		14.40%		6.60%
Time deposits, Percent change		(3.70%)		(0.50%)
Total deposits, Percent change		4.70%		(0.30%)
Total U.S. Bancorp shareholders' equity, Percent change		2.10%		2.40%
Goodwill		$ 1,617	1,619	$ 1,617	1,619
Other intangible assets		50	66	52	68
Assets		13,185	12,248	13,189	12,137
Noninterest-bearing deposits		13,609	14,792	13,458	14,584
Interest checking		8,323	9,824	8,769	10,674
Savings products		49,362	43,154	45,277	42,457
Time deposits		3,747	3,891	3,777	3,796
Total deposits		75,041	71,661	71,281	71,511
Total U.S. Bancorp shareholders' equity		2,528	2,476	2,522	2,464
Payment Services [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)		592	592	$ 1,215	1,202
Net interest income (taxable-equivalent basis), Percent change				1.10%
Noninterest income	[2]	$ 950	902	$ 1,801	1,750
Noninterest income, Percent change		5.30%		2.90%
Total net revenue		$ 1,542	1,494	$ 3,016	2,952
Total net revenue, Percent change		3.20%		2.20%
Noninterest expense, Percent change		4.40%		3.50%
Other intangibles, Percent change		17.90%		16.40%
Total noninterest expense, Percent change		4.90%		4.00%
Income before provision and income taxes, Percent change		1.60%		0.40%
Provision for credit losses, Percent change		5.00%		5.10%
Income before income taxes, Percent change		(0.40%)		(2.40%)
Income taxes and taxable-equivalent adjustment, Percent change				(2.10%)
Net income, Percent change		(0.60%)		(2.40%)
Net income attributable to U.S. Bancorp, Percent change		(0.60%)		(2.40%)
Noninterest expense		$ 736	705	$ 1,458	1,409
Other intangibles		33	28	64	55
Total noninterest expense		769	733	1,522	1,464
Income before provision and income taxes		773	761	1,494	1,488
Provision for credit losses		295	281	581	553
Income before income taxes		478	480	913	935
Income taxes and taxable-equivalent adjustment		120	120	229	234
Net income		358	360	684	701
Net income attributable to U.S. Bancorp		358	360	684	701
Average Balance Sheet
Commercial		$ 10,087	8,963	$ 9,766	8,660
Commercial, Percent change		12.50%		12.80%
Credit card		$ 22,830	21,220	$ 22,714	21,252
Credit card, Percent change		7.60%		6.90%
Other retail		$ 360	408	$ 368	416
Other retail, Percent change		(11.80%)		(11.50%)
Total loans		$ 33,277	30,591	$ 32,848	30,328
Total loans, Percent change		8.80%		8.30%
Goodwill, Percent change		10.70%		10.70%
Other intangible assets, Percent change		36.00%		32.70%
Assets, Percent change		8.20%		7.50%
Noninterest-bearing deposits, Percent change		5.80%		4.20%
Savings products, Percent change		6.60%		5.70%
Time deposits, Percent change		(33.30%)		(33.30%)
Total deposits, Percent change		5.80%		4.20%
Total U.S. Bancorp shareholders' equity, Percent change		6.80%		6.50%
Goodwill		$ 2,806	2,535	$ 2,810	2,538
Other intangible assets		533	392	523	394
Assets		39,519	36,535	39,070	36,348
Noninterest-bearing deposits		1,148	1,085	1,152	1,106
Savings products		113	106	111	105
Time deposits		2	3	2	3
Total deposits		1,263	1,194	1,265	1,214
Total U.S. Bancorp shareholders' equity		7,050	6,601	7,040	6,611
Treasury and Corporate Support [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)		$ 142	107	$ 224	185
Net interest income (taxable-equivalent basis), Percent change		32.70%		21.10%
Noninterest income		$ 266	255	$ 527	459
Noninterest income, Percent change		4.30%		14.80%
Securities gains (losses), net		$ 17	10	$ 22	15
Securities gains (losses), net, Percent change		70.00%		46.70%
Total net revenue		$ 425	372	$ 773	659
Total net revenue, Percent change		14.20%		17.30%
Noninterest expense, Percent change		37.40%		18.20%
Total noninterest expense, Percent change		37.40%		18.20%
Income before provision and income taxes, Percent change		(2.30%)		16.30%
Income before income taxes, Percent change		3.30%		8.70%
Income taxes and taxable-equivalent adjustment, Percent change		(35.30%)		(1.40%)
Net income, Percent change		7.70%		6.50%
Net (income) loss attributable to noncontrolling interests, Percent change		12.50%		(6.70%)
Net income attributable to U.S. Bancorp, Percent change		8.30%		6.50%
Noninterest expense		$ 213	155	$ 409	346
Total noninterest expense		213	155	409	346
Income before provision and income taxes		212	217	364	313
Provision for credit losses		(9)	3	26	2
Income before income taxes		221	214	338	311
Income taxes and taxable-equivalent adjustment		(46)	(34)	(140)	(138)
Net income		267	248	478	449
Net (income) loss attributable to noncontrolling interests		(7)	(8)	(16)	(15)
Net income attributable to U.S. Bancorp		260	240	462	434
Average Balance Sheet
Commercial		$ 1,418	1,104	$ 1,402	1,074
Commercial, Percent change		28.40%		30.50%
Commercial real estate		$ 4,314	4,338	$ 4,315	4,322
Commercial real estate, Percent change		(0.60%)		(0.20%)
Residential mortgages			5		5
Other retail			3		3
Total loans		$ 5,732	5,450	$ 5,717	5,404
Total loans, Percent change		5.20%		5.80%
Assets, Percent change		4.20%		3.30%
Noninterest-bearing deposits, Percent change		(1.80%)		(2.30%)
Savings products, Percent change		2.90%		14.20%
Total deposits, Percent change				91.40%
Total U.S. Bancorp shareholders' equity, Percent change		16.00%		14.80%
Assets		$ 154,830	148,606	$ 153,308	148,354
Noninterest-bearing deposits		2,405	2,448	2,420	2,476
Interest checking		186	38	144	40
Savings products		780	758	826	723
Time deposits		10,050	2,478	9,183	3,329
Total deposits		13,421	5,722	12,573	6,568
Total U.S. Bancorp shareholders' equity		$ 20,761	$ 17,892	$ 20,315	$ 17,698

[1] Includes revenue generated from certain contracts with customers of $1.9 billion for both the three months ended June 30, 2019 and 2018, and $3.6 billion and $3.7 billion for the six months ended June 30, 2019 and 2018, respectively.

[2] Presented net of related rewards and rebate costs and certain partner payments of $566 million and $533 million for the three months ended June 30, 2019 and 2018, respectively, and $1.1 billion for both the six months ended June 30, 2019 and 2018.