Medical Expenses Payable - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2021
Insurance [Abstract]
Claims reserve estimates, excluding provision	$ 935	$ 1,335
Remaining claim amounts payment period		3 years

Claims reserve estimates, excluding provision from prior year claims and claims adjustment expense.

No definition available.

Name:	alhc_ClaimsReserveEstimatesExcludingProvisionFromPriorYearClaimsAndClaimsAdjustmentExpense
Namespace Prefix:	alhc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration