Summary of Significant Accounting Policies - Basis of Consolidation (Narrative) (Details)	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Marketwise, LLC
Significant Accounting Policies [Line Items]
Ownership percentage in subsidiary (as a percent)	12.40%	11.20%	9.10%

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

No definition available.

Name:	us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant