This item refers to the amount of contractual coverage limits for potential losses.

No definition available.

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

- Definition

The ceded percentage of Standard Commercial equipment breakdown coverage.

+ References

No definition available.

+ Details

Name:	hall_CededPercentageOfStandardCommercialEquipmentBreakdownCoverage
Namespace Prefix:	hall_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage of ceded risk to the reinsurers.

+ References

No definition available.

+ Details

Name:	hall_CededRiskPercentage
Namespace Prefix:	hall_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

This amount relates to maximum workers compensation coverage for any one person per loss occurance.

+ References

No definition available.

+ Details

Name:	hall_MaximumWorkersCompensationCoverageForAnyOnePersonPerLossOccurance
Namespace Prefix:	hall_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The proportional reinsurance retention percentage.

+ References

No definition available.

+ Details

Name:	hall_ProportionalReinsuranceRetainingPercentage
Namespace Prefix:	hall_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Excess of loss coverage for each loss occurrence, paid or incurred by the ceding insurer and associated claims settlement expenses on all commercial property risks, including estimated amounts for claims incurred but not reported, and policy benefits, net of any related valuation allowance.

+ References

No definition available.

+ Details

Name:	hall_ReinsuranceRecoverablesForAllCommercialPropertyRisk
Namespace Prefix:	hall_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Excess of loss coverage for each loss occurrence, paid or incurred by the ceding insurer and associated claims settlement expenses on each airport liability loss, including estimated amounts for claims incurred but not reported, and policy benefits, net of any related valuation allowance."

+ References

No definition available.

+ Details

Name:	hall_ReinsuranceRecoverablesForEachAirportLiabilityLoss
Namespace Prefix:	hall_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Excess of loss coverage for each loss occurrence, paid or incurred by the ceding insurer and associated claims settlement expenses on the aircraft hull and liability loss, including estimated amounts for claims incurred but not reported, and policy benefits, net of any related valuation allowance.

+ References

No definition available.

+ Details

Name:	hall_ReinsuranceRecoverablesForEachCombinedAirCraftHullAndLiabilityLoss
Namespace Prefix:	hall_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Excess of loss coverage for each loss occurrence, paid or incurred by the ceding insurer and associated claims settlement expenses on each commercial property risks, including estimated amounts for claims incurred but not reported, and policy benefits, net of any related valuation allowance.

+ References

No definition available.

+ Details

Name:	hall_ReinsuranceRecoverablesForEachCommercialPropertyRisk
Namespace Prefix:	hall_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Excess of loss coverage for each loss occurrence, paid or incurred by the ceding insurer and associated claims settlement expenses for each workers compensation loss, including estimated amounts for claims incurred but not reported, and policy benefits, net of any related valuation allowance.

+ References

No definition available.

+ Details

Name:	hall_ReinsuranceRecoverablesForEachWorkersCompensationLosses
Namespace Prefix:	hall_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The reinsurance percentage for fronting fee with third party.

+ References

No definition available.

+ Details

Name:	hall_ReinsuredPercentageForFrontingFee
Namespace Prefix:	hall_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The aggregate limit per treaty period.

+ References

No definition available.

+ Details

Name:	hall_ReinsurersAggregateLimit
Namespace Prefix:	hall_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount recovered for reinsurance reimbursement losses.

+ References

No definition available.

+ Details

Name:	hall_ReinsurersReimbursementPercentageForSpecifiedLossAmount
Namespace Prefix:	hall_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The retention value of facultative reinsurance which is purchased on any commercial property.

+ References

No definition available.

+ Details

Name:	hall_RetentionValueOfFacultativeReinsurance
Namespace Prefix:	hall_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The maximum retention value limit on losses incurred.

+ References

No definition available.

+ Details

Name:	hall_RetentionValueOfLossIncurred
Namespace Prefix:	hall_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The assumed risk percentage of general agency agreement with an unaffiliated carrier.

+ References

No definition available.

+ Details

Name:	hall_RiskPercentageAssumedOfUnaffliatedCarrier
Namespace Prefix:	hall_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount represents the value of risks for calculating cede percentage which is pertaining to facultative reinsurance.

+ References

No definition available.

+ Details

Name:	hall_ValueOfRisksForCalculatingCededRateFacultativeReinsurance
Namespace Prefix:	hall_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount represents the value of risks for calculating retention percentage which is pertaining to facultative reinsurance.

+ References

No definition available.

+ Details

Name:	hall_ValueOfRisksForCalculatingRetentionRateFacultativeReinsurance
Namespace Prefix:	hall_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The workers compensation loss are limited to aggregate amount for recoverables.

+ References

No definition available.

+ Details

Name:	hall_WorkersCompensationLossAggregateLimit
Namespace Prefix:	hall_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Reinsurance (Details Textual) (USD $) In Millions, unless otherwise specified	6 Months Ended									6 Months Ended					6 Months Ended				1 Months Ended	5 Months Ended
	Jun. 30, 2012	Jun. 30, 2012 E&S Commercial [Member]	Jun. 30, 2012 E&S Commercial [Member] Maximum [Member]	Jun. 30, 2012 E&S Commercial [Member] Minimum [Member]	Jun. 30, 2012 Excess and Umbrella Business Unit [Member]	Jun. 30, 2012 Hallmark County Mutual [Member]	Jun. 30, 2012 Catastrophe [Member]	Jun. 30, 2012 Catastrophe [Member] Maximum [Member]	Jun. 30, 2012 Catastrophe [Member] Minimum [Member]	Jun. 30, 2012 Commercial Property [Member]	Jun. 30, 2012 Commercial Property [Member] Maximum [Member]	Jun. 30, 2012 Commercial Property [Member] Minimum [Member]	Jun. 30, 2012 Commercial Liability Risk [Member]	Jun. 30, 2012 Commercial Liability Risk [Member] Maximum [Member]	Jun. 30, 2012 Aviation Risk [Member]	Jun. 30, 2012 Aviation Risk [Member] Maximum [Member]	Jun. 30, 2012 Workers Compensation Risks [Member]	Jun. 30, 2012 Workers Compensation Risks [Member] Maximum [Member]	Jun. 30, 2012 Medical Professional Liability Risks [Member]	May 31, 2012 Medical Professional Liability Risks [Member]
Retention Value Of Loss Incurred							$ 6.0			$ 1.0			$ 1.0		$ 1.0		$ 1.0
Reinsurers Reimbursement Percentage For Specified Loss Amount							100.00%										100.00%
Reinsurers Aggregate Limit								68.0			30.0
Reinsurance Recoverables For Each Commercial Property Risk										5.0
Reinsurance Recoverables For All Commercial Property Risk												10.0
Retention Value Of Facultative Reinsurance												6.0
Reinsurance Recoverables For Each Combined Air Craft Hull and Liability Loss																5.5
Reinsurance Recoverables For Each Airport Liability Loss																4.0
Reinsurance Recoverables For Each Workers Compensation Losses																		14.0
Maximum Workers Compensation Coverage For Each Person Per Loss Occurance																		10.0
Workers Compensation Loss Aggregate Limit																		28.0
Risk Percentage Assumed Of Unaffliated Carrier, Issuances Prior To 2009					35.00%
Proportional Reinsurance Retaining Percentage		10.00%			20.00%														50.00%	40.00%
Value Of Risks For Calculating Retention Rate Facultative Reinsurance		1.0
Ceded Risk Percentage			100.00%	90.00%	80.00%														50.00%	60.00%
Reinsured Percentage For Fronting Fee						100.00%
Value Of Risks For Calculating Ceded Rate, Facultative Reinsurance		1.0
Amount Of Contractual Coverage Limits For Potential Losses								$ 34.0	$ 6.0					$ 5.0
Ceded Percentage Of Standard Commercial Equipment Breakdown Coverage	100.00%