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Label Element Value
Risk/Return: rr_RiskReturnAbstract  
Document Type dei_DocumentType Other
Document Period End Date dei_DocumentPeriodEndDate Dec. 31, 2011
Registrant Name dei_EntityRegistrantName WANGER ADVISORS TRUST
Central Index Key dei_EntityCentralIndexKey 0000929521
Amendment Flag dei_AmendmentFlag false
Document Creation Date dei_DocumentCreationDate Jan. 24, 2012
Document Effective Date dei_DocumentEffectiveDate Jan. 24, 2012
Prospectus Date rr_ProspectusDate Jan. 24, 2012
(Wanger Select)
  
Risk/Return: rr_RiskReturnAbstract  
Supplement [Text Block] columbia_SupplementTextBlock
WANGER ADVISORS TRUST
Wanger Select
(the "Fund")

Supplement dated January 24, 2011 to the Prospectuses dated May 1, 2011
and the Statement of Additional Information dated May 1, 2011

Effective January 31, 2012, the Fund will no longer be classified as a non-diversified investment company within the meaning of Section 5(b) of the Investment Company Act of 1940.

Effective January 31, 2012, the Fund's prospectuses dated May 1, 2011 are supplemented as follows:
Strategy Narrative Supplement [Text Block] columbia_SupplementTextBlock_02

The last sentence of the fourth paragraph under the heading Principal Investment Strategies is replaced in its entirety with the following:
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

The Fund was previously registered as a non-diversified investment company. Because its investments remained diversified for a period of approximately three years, the Fund lost the ability to invest in a non-diversified manner and is now considered a diversified investment company. The Fund will not be able to become non-diversified unless it seeks and obtains the approval of shareholders.

Risk Narrative Supplement [Text Block] columbia_SupplementTextBlock_01

The last bullet point under the heading Principal Risks is deleted in its entirety.