a.k.a. Brands Holding Corp. Annual report [Section 13 and 15(d), not S-K Item 405]

Annual report [Section 13 and 15(d), not S-K Item 405]

Equity-based Compensation - Narrative (Details)

Equity-based Compensation - Narrative (Details) $ / shares in Units, $ in Millions		1 Months Ended			12 Months Ended
	May 22, 2024 shares	May 31, 2024 tranche $ / shares shares	Sep. 30, 2023 tranche $ / shares shares	Sep. 30, 2021 shares	Dec. 31, 2024 USD ($) tranche $ / shares shares	Dec. 31, 2023 $ / shares shares	May 30, 2023 shares	Dec. 31, 2022 $ / shares	Dec. 31, 2018 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)					0	0
Weighted average exercise price (in dollars per share) \| $ / shares					$ 81.47	$ 81.47		$ 83.36
Vested (in shares)					34,086
2021 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares reserved for issuance (in shares)					2,662,075		833,333
Share-based compensation arrangement by share-based payment award, number of additional shares authorized (in shares)	1,100,000
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period			10 years	10 years
Granted (in shares)			416,667
Number of tranches \| tranche			4
Weighted average exercise price (in dollars per share) \| $ / shares			$ 109.27
Requisite service period			5 years 6 months
Vested (in shares)					0
Unrecognized compensation cost \| $					$ 0.9
Weighted average period (in years)					4 years 2 months 12 days
Stock options \| 2021 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares reserved for issuance (in shares)				408,355
Annual increase of shares authorized for issuance (percent)				1.00%
Unrecognized compensation cost \| $					$ 0.2
Weighted average period (in years)					7 months 6 days
ESPP purchase rights \| 2021 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares reserved for issuance (in shares)				102,088	422,475
Annual increase of shares authorized for issuance (percent)				1.00%
Offering period				6 months
Percentage on share price issued				85.00%
Incentive Units \| 2018 Stock and Incentive Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares reserved for issuance (in shares)									16,475,735
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost \| $					$ 8.2
Weighted average period (in years)					1 year 9 months 18 days
Vesting period				4 years	3 years
RSUs \| Interim CEO Award
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period		5 years
Granted (in shares)		150,000
Number of tranches \| tranche		10
Weighted average exercise price (in dollars per share) \| $ / shares		$ 29.50
Requisite service period		2 years 10 months 24 days
Weighted average period (in years)					1 year 10 months 24 days
Share-based payment arrangement by share-based payment award, number of tranches that achieved targets \| tranche					2
Share-based payment arrangement, nonvested award, cost not yet recognized, amount \| $					$ 0.3
Time-based incentive units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost \| $					$ 0.1
Weighted average period (in years)					3 months 18 days
Vesting period					4 years
Performance-based incentive units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Return multiple					3