Leases - Maturities of Lease Liabilities by Fiscal Year for Operating and Financing Leases (Detail) $ in Thousands	Sep. 30, 2020 USD ($)
Leases [Abstract]
2020 remaining	$ 396
2021	1,574
2022	1,580
2023	1,487
2024	1,112
Thereafter	3,694
Total lease payments	9,843
Less: imputed interest	(1,693)
Present value of lease liabilities	$ 8,150

Lessee, operating and finance lease, liability, present value of net minimum payments.

No definition available.

Name:	hrtg_LesseeOperatingAndFinanceLeaseLiabilityPresentValueOfNetMinimumPayments
Namespace Prefix:	hrtg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Lessee, operating and financing lease, liability, payments, due.

+ References

No definition available.

+ Details

Name:	hrtg_LesseeOperatingAndFinancingLeaseLiabilityPaymentsDue
Namespace Prefix:	hrtg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Lessee, operating and financing lease, liability, payments, due after year five and thereafter.

+ References

No definition available.

+ Details

Name:	hrtg_LesseeOperatingAndFinancingLeaseLiabilityPaymentsDueAfterYearFiveAndThereafter
Namespace Prefix:	hrtg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Lessee, operating and financing lease, liability, payments, due year five.

+ References

No definition available.

+ Details

Name:	hrtg_LesseeOperatingAndFinancingLeaseLiabilityPaymentsDueYearFive
Namespace Prefix:	hrtg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Lessee, operating and financing lease, liability, payments, due year four.

+ References

No definition available.

+ Details

Name:	hrtg_LesseeOperatingAndFinancingLeaseLiabilityPaymentsDueYearFour
Namespace Prefix:	hrtg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Lessee, operating and financing lease, liability, payments, due year three.

+ References

No definition available.

+ Details

Name:	hrtg_LesseeOperatingAndFinancingLeaseLiabilityPaymentsDueYearThree
Namespace Prefix:	hrtg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Lessee, operating and financing lease, liability, payments, due year two.

+ References

No definition available.

+ Details

Name:	hrtg_LesseeOperatingAndFinancingLeaseLiabilityPaymentsDueYearTwo
Namespace Prefix:	hrtg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Lessee, operating and financing lease, liability, payments, remainder of fiscal year.

+ References

No definition available.

+ Details

Name:	hrtg_LesseeOperatingAndFinancingLeaseLiabilityPaymentsRemainderOfFiscalYear
Namespace Prefix:	hrtg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Lessee, operating and financing lease, liability, undiscounted excess amount.

+ References

No definition available.

+ Details

Name:	hrtg_LesseeOperatingAndFinancingLeaseLiabilityUndiscountedExcessAmount
Namespace Prefix:	hrtg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration