Basis of Presentation - Line of Business Financial Performance (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 3,286	$ 3,197
Net interest income (taxable-equivalent basis), Percent change	2.80%
Noninterest income	$ 2,286	2,267
Noninterest income, Percent change	0.80%
Securities gains (losses), net	$ 5	5
Securities gains (losses), net, Percent change	0.00%
Total net revenue	$ 5,577	5,469
Total net revenue, Percent change	2.00%
Noninterest expense, Percent change	1.00%
Other intangibles, Percent change	2.60%
Total noninterest expense, Percent change	1.00%
Income before provision and income taxes, Percent change	3.10%
Provision for credit losses, Percent change	10.60%
Income before income taxes, Percent change	1.90%
Income taxes and taxable-equivalent adjustment, Percent change	3.60%
Net income, Percent change	1.50%
Net (income) loss attributable to noncontrolling interests, Percent change	(28.60%)
Net income attributable to U.S. Bancorp, Percent change	1.40%
Noninterest expense	$ 3,047	3,016
Other intangibles	40	39
Total noninterest expense	3,087	3,055
Income before provision and income taxes	2,490	2,414
Provision for credit losses	377	341
Income before income taxes	2,113	2,073
Income taxes and taxable-equivalent adjustment	405	391
Net income	1,708	1,682
Net (income) loss attributable to noncontrolling interests	(9)	(7)
Net income attributable to U.S. Bancorp	1,699	1,675
Average Balance Sheet
Commercial	$ 101,960	97,465
Commercial, Percent change	4.60%
Commercial real estate	$ 39,470	40,366
Commercial real estate, Percent change	(2.20%)
Residential mortgages	$ 65,582	60,174
Residential mortgages, Percent change	9.00%
Credit card	$ 22,597	21,284
Credit card, Percent change	6.20%
Other retail	$ 56,501	57,051
Other retail, Percent change	(1.00%)
Total loans, excluding covered loans	$ 286,110	276,340
Total loans, excluding covered loans, Percent change	3.50%
Covered loans		3,048
Covered loans, Percent change	0.00%
Total loans	$ 286,110	279,388
Total loans, Percent change	2.40%
Goodwill, Percent change	1.20%
Other intangible assets, Percent change	3.30%
Assets, Percent change	2.00%
Noninterest-bearing deposits, Percent change	(7.60%)
Interest checking, Percent change	2.60%
Savings products, Percent change	(2.10%)
Time deposits, Percent change	22.00%
Total deposits, Percent change	0.20%
Total U.S. Bancorp shareholders' equity, Percent change	5.70%
Goodwill	$ 9,553	9,440
Other intangible assets	3,458	3,349
Assets	463,399	454,288
Noninterest-bearing deposits	73,433	79,482
Interest checking	72,177	70,358
Savings products	144,648	147,755
Time deposits	45,108	36,985
Total deposits	335,366	334,580
Total U.S. Bancorp shareholders' equity	51,589	48,825
Corporate and Commercial Banking [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 725	722
Net interest income (taxable-equivalent basis), Percent change	0.40%
Noninterest income	$ 210	207
Noninterest income, Percent change	1.40%
Securities gains (losses), net, Percent change	0.00%
Total net revenue	$ 935	929
Total net revenue, Percent change	0.60%
Noninterest expense, Percent change	3.80%
Total noninterest expense, Percent change	3.80%
Income before provision and income taxes, Percent change	(1.70%)
Income before income taxes, Percent change	3.10%
Income taxes and taxable-equivalent adjustment, Percent change	3.10%
Net income, Percent change	3.10%
Net income attributable to U.S. Bancorp, Percent change	3.10%
Noninterest expense	$ 411	396
Other intangibles	1	1
Total noninterest expense	412	397
Income before provision and income taxes	523	532
Provision for credit losses	(11)	14
Income before income taxes	534	518
Income taxes and taxable-equivalent adjustment	134	130
Net income	400	388
Net income attributable to U.S. Bancorp	400	388
Average Balance Sheet
Commercial	$ 77,761	74,755
Commercial, Percent change	4.00%
Commercial real estate	$ 18,644	19,131
Commercial real estate, Percent change	(2.50%)
Residential mortgages	$ 6	6
Total loans, excluding covered loans	$ 96,411	93,892
Total loans, excluding covered loans, Percent change	2.70%
Covered loans, Percent change	0.00%
Total loans	$ 96,411	93,892
Total loans, Percent change	2.70%
Other intangible assets, Percent change	(25.00%)
Assets, Percent change	2.50%
Noninterest-bearing deposits, Percent change	(12.50%)
Interest checking, Percent change	23.80%
Savings products, Percent change	(6.30%)
Time deposits, Percent change	10.10%
Total deposits, Percent change	(3.00%)
Total U.S. Bancorp shareholders' equity, Percent change	0.20%
Goodwill	$ 1,647	1,647
Other intangible assets	9	12
Assets	105,144	102,582
Noninterest-bearing deposits	29,979	34,278
Interest checking	11,753	9,491
Savings products	41,145	43,926
Time deposits	18,195	16,522
Total deposits	101,072	104,217
Total U.S. Bancorp shareholders' equity	10,439	10,416
Consumer and Business Banking [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 1,568	1,512
Net interest income (taxable-equivalent basis), Percent change	3.70%
Noninterest income	$ 533	571
Noninterest income, Percent change	(6.70%)
Securities gains (losses), net, Percent change	0.00%
Total net revenue	$ 2,101	2,083
Total net revenue, Percent change	0.90%
Noninterest expense, Percent change	(0.80%)
Other intangibles, Percent change	(28.60%)
Total noninterest expense, Percent change	(0.90%)
Income before provision and income taxes, Percent change	3.80%
Provision for credit losses, Percent change	27.30%
Income before income taxes, Percent change	2.10%
Income taxes and taxable-equivalent adjustment, Percent change	2.20%
Net income, Percent change	2.00%
Net income attributable to U.S. Bancorp, Percent change	2.00%
Noninterest expense	$ 1,286	1,296
Other intangibles	5	7
Total noninterest expense	1,291	1,303
Income before provision and income taxes	810	780
Provision for credit losses	70	55
Income before income taxes	740	725
Income taxes and taxable-equivalent adjustment	185	181
Net income	555	544
Net income attributable to U.S. Bancorp	555	544
Average Balance Sheet
Commercial	$ 9,451	9,651
Commercial, Percent change	(2.10%)
Commercial real estate	$ 16,005	16,419
Commercial real estate, Percent change	(2.50%)
Residential mortgages	$ 61,906	57,049
Residential mortgages, Percent change	8.50%
Other retail	$ 54,395	54,925
Other retail, Percent change	(1.00%)
Total loans, excluding covered loans	$ 141,757	138,044
Total loans, excluding covered loans, Percent change	2.70%
Covered loans		3,048
Covered loans, Percent change	0.00%
Total loans	$ 141,757	141,092
Total loans, Percent change	0.50%
Goodwill, Percent change	(4.30%)
Other intangible assets, Percent change	0.40%
Assets, Percent change	(0.50%)
Noninterest-bearing deposits, Percent change	(2.40%)
Interest checking, Percent change	3.80%
Savings products, Percent change	0.20%
Time deposits, Percent change	17.70%
Total deposits, Percent change	2.40%
Total U.S. Bancorp shareholders' equity, Percent change	(0.80%)
Goodwill	$ 3,475	3,632
Other intangible assets	2,882	2,871
Assets	154,743	155,488
Noninterest-bearing deposits	26,570	27,210
Interest checking	51,149	49,299
Savings products	61,395	61,292
Time deposits	14,798	12,570
Total deposits	153,912	150,371
Total U.S. Bancorp shareholders' equity	11,747	11,842
Wealth Management and Investment Services [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 288	275
Net interest income (taxable-equivalent basis), Percent change	4.70%
Noninterest income	$ 430	431
Noninterest income, Percent change	(0.20%)
Securities gains (losses), net, Percent change	0.00%
Total net revenue	$ 718	706
Total net revenue, Percent change	1.70%
Noninterest expense, Percent change	2.80%
Other intangibles, Percent change	(25.00%)
Total noninterest expense, Percent change	2.60%
Income before provision and income taxes, Percent change	0.40%
Income before income taxes, Percent change	1.80%
Income taxes and taxable-equivalent adjustment, Percent change	1.40%
Net income, Percent change	1.90%
Net income attributable to U.S. Bancorp, Percent change	1.90%
Noninterest expense	$ 435	423
Other intangibles	3	4
Total noninterest expense	438	427
Income before provision and income taxes	280	279
Provision for credit losses	(3)	1
Income before income taxes	283	278
Income taxes and taxable-equivalent adjustment	71	70
Net income	212	208
Net income attributable to U.S. Bancorp	212	208
Average Balance Sheet
Commercial	$ 3,921	3,661
Commercial, Percent change	7.10%
Commercial real estate	$ 504	511
Commercial real estate, Percent change	(1.40%)
Residential mortgages	$ 3,670	3,113
Residential mortgages, Percent change	17.90%
Other retail	$ 1,730	1,699
Other retail, Percent change	1.80%
Total loans, excluding covered loans	$ 9,825	8,984
Total loans, excluding covered loans, Percent change	9.40%
Covered loans, Percent change	0.00%
Total loans	$ 9,825	8,984
Total loans, Percent change	9.40%
Goodwill, Percent change	(0.10%)
Other intangible assets, Percent change	(22.90%)
Assets, Percent change	9.70%
Noninterest-bearing deposits, Percent change	(7.40%)
Interest checking, Percent change	(20.40%)
Savings products, Percent change	(1.50%)
Time deposits, Percent change	2.90%
Total deposits, Percent change	(5.50%)
Total U.S. Bancorp shareholders' equity, Percent change	2.60%
Goodwill	$ 1,617	1,619
Other intangible assets	54	70
Assets	13,187	12,026
Noninterest-bearing deposits	13,293	14,361
Interest checking	9,175	11,525
Savings products	41,127	41,747
Time deposits	3,806	3,700
Total deposits	67,401	71,333
Total U.S. Bancorp shareholders' equity	2,515	2,451
Payment Services [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 622	611
Net interest income (taxable-equivalent basis), Percent change	1.80%
Noninterest income	$ 853	848
Noninterest income, Percent change	0.60%
Securities gains (losses), net, Percent change	0.00%
Total net revenue	$ 1,475	1,459
Total net revenue, Percent change	1.10%
Noninterest expense, Percent change	2.80%
Other intangibles, Percent change	14.80%
Total noninterest expense, Percent change	3.30%
Income before provision and income taxes, Percent change	(1.10%)
Provision for credit losses, Percent change	5.10%
Income before income taxes, Percent change	(4.90%)
Income taxes and taxable-equivalent adjustment, Percent change	(4.40%)
Net income, Percent change	(5.00%)
Net income attributable to U.S. Bancorp, Percent change	(5.00%)
Noninterest expense	$ 728	708
Other intangibles	31	27
Total noninterest expense	759	735
Income before provision and income taxes	716	724
Provision for credit losses	286	272
Income before income taxes	430	452
Income taxes and taxable-equivalent adjustment	108	113
Net income	322	339
Net income attributable to U.S. Bancorp	322	339
Average Balance Sheet
Commercial	$ 9,441	8,354
Commercial, Percent change	13.00%
Credit card	$ 22,597	21,284
Credit card, Percent change	6.20%
Other retail	$ 376	424
Other retail, Percent change	(11.30%)
Total loans, excluding covered loans	$ 32,414	30,062
Total loans, excluding covered loans, Percent change	7.80%
Covered loans, Percent change	0.00%
Total loans	$ 32,414	30,062
Total loans, Percent change	7.80%
Goodwill, Percent change	10.70%
Other intangible assets, Percent change	29.50%
Assets, Percent change	6.80%
Noninterest-bearing deposits, Percent change	2.70%
Savings products, Percent change	5.80%
Time deposits, Percent change	(33.30%)
Total deposits, Percent change	2.80%
Total U.S. Bancorp shareholders' equity, Percent change	6.10%
Goodwill	$ 2,814	2,542
Other intangible assets	513	396
Assets	38,618	36,161
Noninterest-bearing deposits	1,157	1,127
Savings products	109	103
Time deposits	2	3
Total deposits	1,268	1,233
Total U.S. Bancorp shareholders' equity	7,024	6,621
Treasury and Corporate Support [Member]
Condensed Income Statement
Net interest income (taxable-equivalent basis)	$ 83	77
Net interest income (taxable-equivalent basis), Percent change	7.80%
Noninterest income	$ 260	210
Noninterest income, Percent change	23.80%
Securities gains (losses), net	$ 5	5
Securities gains (losses), net, Percent change	0.00%
Total net revenue	$ 348	292
Total net revenue, Percent change	19.20%
Noninterest expense, Percent change	(3.10%)
Total noninterest expense, Percent change	(3.10%)
Income before provision and income taxes, Percent change	62.60%
Income before income taxes, Percent change	26.00%
Income taxes and taxable-equivalent adjustment, Percent change	9.70%
Net income, Percent change	7.90%
Net (income) loss attributable to noncontrolling interests, Percent change	(28.60%)
Net income attributable to U.S. Bancorp, Percent change	7.10%
Noninterest expense	$ 187	193
Total noninterest expense	187	193
Income before provision and income taxes	161	99
Provision for credit losses	35	(1)
Income before income taxes	126	100
Income taxes and taxable-equivalent adjustment	(93)	(103)
Net income	219	203
Net (income) loss attributable to noncontrolling interests	(9)	(7)
Net income attributable to U.S. Bancorp	210	196
Average Balance Sheet
Commercial	$ 1,386	1,044
Commercial, Percent change	32.80%
Commercial real estate	$ 4,317	4,305
Commercial real estate, Percent change	0.30%
Residential mortgages		6
Other retail		3
Total loans, excluding covered loans	$ 5,703	5,358
Total loans, excluding covered loans, Percent change	6.40%
Covered loans, Percent change	0.00%
Total loans	$ 5,703	5,358
Total loans, Percent change	6.40%
Assets, Percent change	2.50%
Noninterest-bearing deposits, Percent change	(2.90%)
Savings products, Percent change	26.90%
Time deposits, Percent change	98.30%
Total deposits, Percent change	57.70%
Total U.S. Bancorp shareholders' equity, Percent change	13.50%
Assets	$ 151,707	148,031
Noninterest-bearing deposits	2,434	2,506
Interest checking	100	43
Savings products	872	687
Time deposits	8,307	4,190
Total deposits	11,713	7,426
Total U.S. Bancorp shareholders' equity	$ 19,864	$ 17,495