PROHIBITED TRANSACTIONS (Details) - EBP 004	12 Months Ended
Dec. 31, 2024 USD ($)
EBP, Risk and Uncertainty [Line Items]
Participant contribution not timely deposited into participant accounts	$ 522
Matching employer contribution not timely deposited into participant accounts	253
Loan payment not timely deposited into participant accounts	$ 744

EBP, Employer Contribution, Amount Not Timely Deposited Into Participant Accounts

No definition available.

Name:	unp_EBPEmployerContributionAmountNotTimelyDepositedIntoParticipantAccounts
Namespace Prefix:	unp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

EBP, Participant Contribution, Amount Not Timely Deposited Into Participant Accounts

+ References

No definition available.

+ Details

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Namespace Prefix:	unp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

EBP, Participant Loan, Payment Not Timely Deposited Into Participant Accounts

+ References

No definition available.

+ Details

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Namespace Prefix:	unp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 275
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482861/275-10-50-18

+ Details

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Namespace Prefix:	us-gaap-ebp_
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Period Type:	duration

- Details

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Namespace Prefix:
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Balance Type:
Period Type: