XML 59 R49.htm IDEA: XBRL DOCUMENT
v3.21.2

Accounts Receivable (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2021 | Jun. 30, 2020 | Jun. 30, 2021 | Jun. 30, 2020 | Dec. 31, 2020
Accounts Receivable Details [Abstract] |  |  |  |  |
Allowance for doubtful accounts | $ 12 |  | $ 12 |  | $ 17
Allowance for doubtful accounts - receivables not expected to be collected in one year | 45 |  | 45 |  | 51
Receivables Securitization Facility [Abstract] |  |  |  |  |
Total capacity to transfer undivided interests to investors under the receivables securitization facility | 800 |  | $ 800 |  |
Receivables securitization facility maturity date |  |  | 2022-07 |  |
Receivables securitization facility duration |  |  | 3 years |  |
Value of the outstanding undivided interest held by investors under the receivables securitization facility | 400 |  | $ 400 |  | 0
Accounts receivable supporting the undivided interest held by investors | 1,300 |  | 1,300 |  | $ 1,200
Cost of the receivables securitization facility - interest expense | $ 1 | $ 1 | $ 2 | $ 4 |

X
- Definition The value of the accounts receivable that supported the value of the undivided interest held by investors. + References No definition available. + Details
Name: | unp_AccountsReceivableSupportingUndividedInvestorHeldInterest
Namespace Prefix: | unp_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | unp_ReceivablesSecuritizationFacilityAbstract
Namespace Prefix: | unp_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Duration of the receivables securitization facility,in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | unp_ReceivablesSecuritizationFacilityDuration
Namespace Prefix: | unp_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Interest expense associated with maintaining the receivables securitization facility. + References No definition available. + Details
Name: | unp_ReceivablesSecuritizationFacilityInterestExpenseCost
Namespace Prefix: | unp_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Maturity date the receivables securitization facility, in Year Month format. + References No definition available. + Details
Name: | unp_ReceivablesSecuritizationFacilityMaturityDate
Namespace Prefix: | unp_
Data Type: | xbrli:gYearMonthItemType
Balance Type: | na
Period Type: | duration

X
- Definition Total capacity to transfer undivided interest to investors under receivables securitization facility. + References No definition available. + Details
Name: | unp_TotalTransferCapacityUndividedInterestsToInvestorsUnderReceivablesSecuritizationFacility
Namespace Prefix: | unp_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Value of the outstanding undivided interest held by investors under the receivables securitization facility. + References No definition available. + Details
Name: | unp_ValueOutstandingUndividedInterestHeldByInvestorsUnderReceivablesSecuritizationFacility
Namespace Prefix: | unp_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_AccountsReceivableAdditionalDisclosuresAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of allowance for credit loss on accounts receivable, classified as current. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(4) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5074-111524 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=121599878&loc=SL82895884-210446 + Details
Name: | us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of allowance for credit loss on accounts receivable, classified as noncurrent. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5074-111524 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=121599878&loc=SL82895884-210446 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(4)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_AllowanceForDoubtfulAccountsReceivableNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant