Business (Details)	Sep. 30, 2025 member
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of medicare advantage members enrolled with private health plans	502,800

Number of Medicare Advantage members enrolled with private health plans.

No definition available.

Name:	agl_NumberOfMedicareAdvantageMembersEnrolledWithPrivateHealthPlans
Namespace Prefix:	agl_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant