Equity-based Compensation - Schedule of Grant Date Fair Value (Details) - $ / shares	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares)	0	2,820,000	2,070,000
Weighed average fair value (in dollars per share)	$ 0	$ 0.65	$ 2.48
Brightsphere Equity Incentive Plan \| Restricted shares (RSA)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares)	0	0	18,000
Granted during the year (in dollars per share)	$ 0	$ 0	$ 10.09
Brightsphere Equity Incentive Plan \| Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares)	15,548	105,678	88,980
Granted during the year (in dollars per share)	$ 22.06	$ 10.20	$ 12.40
Brightsphere Equity Incentive Plan \| Performance-based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares)	0	0	9,013
Granted during the year (in dollars per share)	$ 0	$ 0	$ 14.62
Brightsphere Equity Incentive Plan \| Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares)	0	2,820,000	2,070,000
Weighed average fair value (in dollars per share)	$ 0	$ 0.65	$ 2.48

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
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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.

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Net number of non-option equity instruments granted to participants.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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Gross number of share options (or share units) granted during the period.

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The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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