COMMITMENTS: Level 4 (Details) $ in Millions	9 Months Ended
Sep. 30, 2016 USD ($)
Idaho Power Company
Guarantor Obligations
IERCo ownership interest in BCC	33.00%
IERCo guarantee of BCC reclamation obligation	$ 71
Long-term Purchase Commitment
Reduction of Long-term Purchase Commitment, Amount	$ 267
Life of Contract	20 years
Bridger Coal Company
Guarantor Obligations
Guarantor Obligations Total Reclamation Trust Fund	$ 79
Distribution from Reclamation Trust Fund	$ 1

Distribution from Reclamation Trust Fund related to the guarantee obligation that exists at the balance sheet date.

No definition available.

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

- Definition

Total reclamation trust fund balance related to the guarantee obligation that exists at the balance sheet date.

+ References

No definition available.

+ Details

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Namespace Prefix:	ida_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Life of Contract

+ References

No definition available.

+ Details

Name:	ida_LifeofContract
Namespace Prefix:	ida_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The estimated reduction amount the entity agreed to spend under long-term purchase commitment(s).

+ References

No definition available.

+ Details

Name:	ida_ReductionofLongtermPurchaseCommitmentAmount
Namespace Prefix:	ida_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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

No definition available.

+ Details

Name:	us-gaap_GuaranteeObligationsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_LongTermCommitmentExcludingUnconditionalPurchaseObligationAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 5A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=64801991&loc=SL6759159-111685

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	dei_LegalEntityAxis=ida_IdahoPowerCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=ida_BridgerCoalCompanyMember
Namespace Prefix:
Data Type:	na
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Period Type: