v3.26.3
S000010309 [Member] Expense Example - AB Small Cap Growth Portfolio
Jun. 30, 2026
USD ($)
Class A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year $ 536
Expense Example, with Redemption, 3 Years 772
Expense Example, with Redemption, 5 Years 1,026
Expense Example, with Redemption, 10 Years 1,752
Class C  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 292 [1]
Expense Example, with Redemption, 3 Years 594
Expense Example, with Redemption, 5 Years 1,021
Expense Example, with Redemption, 10 Years 2,016
Advisor Class  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 91
Expense Example, with Redemption, 3 Years 284
Expense Example, with Redemption, 5 Years 493
Expense Example, with Redemption, 10 Years 1,096
Class I  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 91
Expense Example, with Redemption, 3 Years 284
Expense Example, with Redemption, 5 Years 493
Expense Example, with Redemption, 10 Years 1,096
Class Z  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 81
Expense Example, with Redemption, 3 Years 254
Expense Example, with Redemption, 5 Years 443
Expense Example, with Redemption, 10 Years $ 989
[1]
If you did not redeem your shares at the end of the period, your expenses would be decreased by approximately $100.