Pledged Investments (Details Textual) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Securities Available-for-sale Pledged, Carrying Value	$ 22.1	$ 24.3

The carrying value of available-for-sale securities that serve as collateral for borrowings.

No definition available.

Name:	hall_SecuritiesAvailableForSalePledgedCarryingValue
Namespace Prefix:	hall_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant