XML 61 R50.htm IDEA: XBRL DOCUMENT v3.21.2

Stockholders' Equity - Dividends Declared (Details) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Dividends Declared [Line Items]
Dividends declared per Class A common share (in dollars per share)	$ 1.00	$ 0.67	$ 3.16	$ 2.56
Quarterly
Dividends Declared [Line Items]
Dividends declared per Class A common share (in dollars per share)	1.00	0.67	2.85	1.96
Special Annual
Dividends Declared [Line Items]
Dividends declared per Class A common share (in dollars per share)	$ 0	$ 0	$ 0.31	$ 0.60

X

- Definition

Aggregate dividends paid during the period for each share of common stock outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

+ Details

Name:	us-gaap_CommonStockDividendsPerShareCashPaid
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	duration

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

X

- Details

Name:	us-gaap_DividendsAxis=apam_QuarterlyCashDividendMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DividendsAxis=apam_SpecialAnnualDividendMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: