Business Acquisition Adjusted Contract Price

No definition available.

Name:	ava_BusinessAcquisitionAdjustedContractPrice
Namespace Prefix:	ava_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Business Acquisition Contract Price

+ References

No definition available.

+ Details

Name:	ava_BusinessAcquisitionContractPrice
Namespace Prefix:	ava_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Business Acquisition, Contract Price Closing Adjustments

+ References

No definition available.

+ Details

Name:	ava_BusinessAcquisitionContractPriceClosingAdjustments
Namespace Prefix:	ava_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Business Acquisition, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current and Long-Term Debt

+ References

No definition available.

+ Details

Name:	ava_BusinessAcquisitionRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedCurrentandLongTermDebt
Namespace Prefix:	ava_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

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

- Definition

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 30

-Paragraph 7

-URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6578-128477

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 30

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6613-128477

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479

+ Details

Name:	us-gaap_BusinessCombinationConsiderationTransferred1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of equity interests of the acquirer, including instruments or interests issued or issuable in consideration for the business combination.

+ References

+ Details

Name:	us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of currency on hand as well as demand deposits with banks or financial institutions, acquired at the acquisition date. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=39739317&loc=d3e4845-128472

+ Details

Name:	us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 13

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3213-108585

+ Details

Name:	us-gaap_PaymentsToAcquireBusinessesGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Business Acquisitions Contract Price and Fair Value of Consideration Transferred (Details) (USD $) In Thousands, unless otherwise specified	0 Months Ended		12 Months Ended
	Oct. 01, 2014	Jul. 01, 2014	Dec. 31, 2014	Jul. 01, 2014
Business Acquisition [Line Items]
Merger Consideration - Total				$ 170,000ava_BusinessAcquisitionContractPrice
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents				19,704
Business Acquisition Recognized Identifiable Assets Acquired and Liabilities Assumed Current and Long-Term Debt				(38,832)
Business Acquisition Contract Price Closing Adjustments				(58)
Business Acquisition Adjusted Contract Price				150,814
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable	44	150,075
Payments to Acquire Businesses, Gross			4,697
Business Combination, Consideration Transferred		$ 154,816