Additional coverage percentage of gross quota share.

No definition available.

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- Definition

Number of layers in excess of retention loss.

+ References

No definition available.

+ Details

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Namespace Prefix:	hrtg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of loss applied to reinsurance contract.

+ References

No definition available.

+ Details

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Namespace Prefix:	hrtg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of reinstatements available with premium.

+ References

No definition available.

+ Details

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Namespace Prefix:	hrtg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of gross quota share.

+ References

No definition available.

+ Details

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Namespace Prefix:	hrtg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Liability evolves to a reinsurer as a ramification of the ceding company's or primary insurer's liability per loss occurrence.

+ References

No definition available.

+ Details

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Namespace Prefix:	hrtg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Namespace Prefix:	srt_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount needed to reflect the estimated ultimate cost of settling claims relating to insured events that have occurred on or before the balance sheet date, whether or not reported to the insurer at that date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=116884095&loc=d3e14764-158437

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-SubTopic 40
-Section 50
-Paragraph 3
-Subparagraph (cc)
-URI http://asc.fasb.org/extlink&oid=116884095&loc=d3e14764-158437

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Cash payments made for reinsurance during the current period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 25
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3536-108585

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The carrying amount as of the balance sheet date of the known and estimated amounts owed to insurers under reinsurance treaties or other arrangements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.13(a)(3),(c))
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Stated amount that is the upper retention limit per entity policy.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of risk reinsured in excess of stated retention per company policy.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

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Reinsurance - 2018-2019 Reinsurance Programs - Additional information - (Detail)	12 Months Ended
	Dec. 31, 2019 USD ($) Reinsurer	Dec. 31, 2018 USD ($) Reinsurer Layer	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Reinsurance Premiums For Insurance Companies By Product Segment [Line Items]
Unpaid losses and loss adjustment expenses	$ 613,533,000	$ 432,359,000	$ 470,083,000	$ 140,137,000
Reinsurance payable	$ 156,351,000	$ 166,975,000
Number of reinstatements available \| Reinsurer	2	2
NBIC [Member]
Reinsurance Premiums For Insurance Companies By Product Segment [Line Items]
Retention under program to provide reinsurance coverage	$ 1,000,000,000
Primary retention	18,500,000
Facultative Reinsurance [Member] \| Maximum [Member]
Reinsurance Premiums For Insurance Companies By Product Segment [Line Items]
Reinsurance payable	10,000,000	$ 10,000,000
Facultative Reinsurance [Member] \| Minimum [Member]
Reinsurance Premiums For Insurance Companies By Product Segment [Line Items]
Facultative reinsurance purchase amount	10,000,000	$ 10,000,000
Facultative Reinsurance [Member] \| Minimum [Member] \| NBIC [Member]
Reinsurance Premiums For Insurance Companies By Product Segment [Line Items]
Reinsurance payable	3,500,000
General Excess of Loss 2018-2019 Reinsurance Program [Member] \| NBIC [Member]
Reinsurance Premiums For Insurance Companies By Product Segment [Line Items]
Number of loss applied to reinsurance contract \| Reinsurer		1
Number of layers in excess of retention loss \| Layer		2
Retention under program to provide reinsurance coverage		$ 300,000
General Excess of Loss 2018-2019 Reinsurance Program [Member] \| NBIC [Member] \| First Layer Coverage [Member]
Reinsurance Premiums For Insurance Companies By Product Segment [Line Items]
Retention under program to provide reinsurance coverage		450,000
Primary retention		300,000
General Excess of Loss 2018-2019 Reinsurance Program [Member] \| NBIC [Member] \| Second Layer Coverage
Reinsurance Premiums For Insurance Companies By Product Segment [Line Items]
Retention under program to provide reinsurance coverage		2,750,000
Primary retention		750,000
General Excess of Loss 2018-2019 Reinsurance Program [Member] \| NBIC [Member] \| Casualty Second Layer [Member]
Reinsurance Premiums For Insurance Companies By Product Segment [Line Items]
Retention under program to provide reinsurance coverage		1,250,000
Primary retention		$ 750,000
General Excess of Loss 2018-2019 Reinsurance Program [Member] \| NBIC [Member] \| First and Second Layer Coverage [Member]
Reinsurance Premiums For Insurance Companies By Product Segment [Line Items]
Percentage of gross quota share		92.00%
Additional coverage percentage of gross quota share		8.00%
Facultative 2018 - 2019 Reinsurance Program [Member] \| Minimum [Member] \| NBIC [Member]
Reinsurance Premiums For Insurance Companies By Product Segment [Line Items]
Reinsurance payable		$ 3,500,000
Insurance Claims [Member]
Reinsurance Premiums For Insurance Companies By Product Segment [Line Items]
Unpaid losses and loss adjustment expenses	1,000,000	1,000,000
Property Per Risk Coverage [Member]
Reinsurance Premiums For Insurance Companies By Product Segment [Line Items]
Coverage limit	9,000,000	9,000,000
Reinsurance payable	$ 27,000,000	$ 27,000,000