Deferred Sales Commissions, Net - Schedule of Future Amortization Expense (Details) $ in Thousands	12 Months Ended
Dec. 31, 2020 USD ($)
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
2021	$ 28,980
2022	23,631
2023	10,787
2024	668
Total	$ 64,066

The amount of amortization expense expected to be recognized during year four of the six succeeding fiscal years.

No definition available.

Name:	ablp_DeferredSalesCommissionFutureAmortizationExpenseYearFour
Namespace Prefix:	ablp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The amount of amortization expense expected to be recognized during year one of the six succeeding fiscal years.

No definition available.

Name:	ablp_DeferredSalesCommissionFutureAmortizationExpenseYearOne
Namespace Prefix:	ablp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The amount of amortization expense expected to be recognized during year three of the six succeeding fiscal years.

No definition available.

Name:	ablp_DeferredSalesCommissionFutureAmortizationExpenseYearThree
Namespace Prefix:	ablp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The amount of amortization expense expected to be recognized during year two of the six succeeding fiscal years.

No definition available.

Name:	ablp_DeferredSalesCommissionFutureAmortizationExpenseYearTwo
Namespace Prefix:	ablp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The aggregate estimated amortization expense for succeeding fiscal years for deferred sales commissions subject to amortization.

No definition available.

Name:	ablp_DeferredSalesCommissionsFutureAmortizationExpense
Namespace Prefix:	ablp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

No definition available.

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