XML 48 R38.htm IDEA: XBRL DOCUMENT
v3.23.3

Investment Securities - Additional Information (Details) - USD ($) $ in Millions | Sep. 30, 2023 | Dec. 31, 2022
--- | --- | ---
Long-Term Cash Awards |  |
Marketable Securities [Line Items] |  |
Investments | $ 96.6 | $ 63.3

X
- Definition Sum of the carrying amounts as of the balance sheet date of all investments. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(1)(h)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479440/944-210-S99-1 + Details
Name: | us-gaap_Investments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_MarketableSecuritiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_AwardTypeAxis=apam_LongTermCashAwardsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |