Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

WANGER ADVISORS TRUST

Prospectus Date

rr_ProspectusDate

May 01, 2015

Supplement [Text Block]

wat1_SupplementTextBlock

Supplement dated May 1, 2015

to the Prospectus of the following Fund:

Fund	Prospectus Dated
Wanger Advisors Trust
Wanger Select	05/01/2015

Effective May 1, 2015, the following changes are made to the Fund’s prospectus:

The Annual Fund Operating Expenses table under the caption “Fees and Expenses of the Fund" in the “Summary of the Fund" section is hereby superseded and replaced with the following:

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management fees	0.80%
Distribution and/or service (12b-1) fees	0.00%
Other expenses	0.13%
Total annual Fund operating expenses	0.93%
Less: Fee waivers and/or expense reimbursements(a)	(0.20%)
Total annual Fund operating expenses after fee waivers and/or expense reimbursements	0.73%

(a) Effective May 1, 2015, Columbia Wanger Asset Management, LLC (the Investment Manager) has contractually agreed to waive 0.20% of the advisory fee otherwise payable to it by the Fund through April 30, 2016. This arrangement may only be modified or amended with approval from all parties to the arrangement, including the Fund and the Investment Manager.

The expense example table under the caption “Fees and Expenses of the Fund – Example”, and the paragraph that immediately precedes it, in the “Summary of the Fund” section is hereby superseded and replaced with the following:

Since the waivers and/or reimbursements shown in the Annual Fund Operating Expenses table above expire as indicated in the preceding table, they are only reflected in the 1 year example and the first year of the other examples. Although your actual costs may be higher or lower, based on the assumptions listed above, your costs would be:

	1 year	3 years	5 years	10 years
Wanger Select (whether or not shares are redeemed)	$75	$276	$495	$1,125

Wanger Select

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

wat1_SupplementTextBlock

Supplement dated May 1, 2015

to the Prospectus of the following Fund:

Fund	Prospectus Dated
Wanger Advisors Trust
Wanger Select	05/01/2015

Effective May 1, 2015, the following changes are made to the Fund’s prospectus:

The Annual Fund Operating Expenses table under the caption “Fees and Expenses of the Fund" in the “Summary of the Fund" section is hereby superseded and replaced with the following:

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management fees	0.80%
Distribution and/or service (12b-1) fees	0.00%
Other expenses	0.13%
Total annual Fund operating expenses	0.93%
Less: Fee waivers and/or expense reimbursements(a)	(0.20%)
Total annual Fund operating expenses after fee waivers and/or expense reimbursements	0.73%

(a) Effective May 1, 2015, Columbia Wanger Asset Management, LLC (the Investment Manager) has contractually agreed to waive 0.20% of the advisory fee otherwise payable to it by the Fund through April 30, 2016. This arrangement may only be modified or amended with approval from all parties to the arrangement, including the Fund and the Investment Manager.

The expense example table under the caption “Fees and Expenses of the Fund – Example”, and the paragraph that immediately precedes it, in the “Summary of the Fund” section is hereby superseded and replaced with the following:

Since the waivers and/or reimbursements shown in the Annual Fund Operating Expenses table above expire as indicated in the preceding table, they are only reflected in the 1 year example and the first year of the other examples. Although your actual costs may be higher or lower, based on the assumptions listed above, your costs would be:

	1 year	3 years	5 years	10 years
Wanger Select (whether or not shares are redeemed)	$75	$276	$495	$1,125

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

April 30, 2016

Wanger Select | Wanger Select

Risk/Return:

rr_RiskReturnAbstract

Management fees

rr_ManagementFeesOverAssets

0.80%

Distribution and/or service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.13%

Total annual Fund operating expenses

rr_ExpensesOverAssets

0.93%

Less: Fee waivers and/or expense reimbursements

rr_FeeWaiverOrReimbursementOverAssets

(0.20%)

^[1]

Total annual Fund operating expenses after fee waivers and/or expense reimbursements

rr_NetExpensesOverAssets

0.73%

1 year

rr_ExpenseExampleYear01

75

3 years

rr_ExpenseExampleYear03

276

5 years

rr_ExpenseExampleYear05

495

10 years

rr_ExpenseExampleYear10

1,125

1 year

rr_ExpenseExampleNoRedemptionYear01

75

3 years

rr_ExpenseExampleNoRedemptionYear03

276

5 years

rr_ExpenseExampleNoRedemptionYear05

495

10 years

rr_ExpenseExampleNoRedemptionYear10

1,125

[1] Effective May 1, 2015, Columbia Wanger Asset Management, LLC (the Investment Manager) has contractually agreed to waive 0.20% of the advisory fee otherwise payable to it by the Fund through April 30, 2016. This arrangement may only be modified or amended with approval from all parties to the arrangement, including the Fund and the Investment Manager.