Business - Additional Information (Details)	Mar. 31, 2022 Medicare
Description of Business [Line Items]
Number of medicare advantage members enrolled with private health plans	250,300

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