Fair Value (Narrative) (Details) - security	9 Months Ended	12 Months Ended
Sep. 30, 2023	Dec. 31, 2022
Fair Value [Abstract]
Number of debt securities with unobservable inputs	0	0

Available-For-Sale Securities, Number Of Debt Securities With Unobservable Inputs

No definition available.

Name:	hall_AvailableForSaleSecuritiesNumberOfDebtSecuritiesWithUnobservableInputs
Namespace Prefix:	hall_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration