Reinsurance coverage, maximum provisional limit, amount

No definition available.

Name:	uihc_AggregateCoverageForCoveredLossesUnderReinsuranceContract
Namespace Prefix:	uihc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

According to the ISO, a catastrophe loss is defined as a single unpredictable incident or series of closely related incidents that result in at least this amount in U.S industry-wide direct insured losses to property.

+ References

No definition available.

+ Details

Name:	uihc_ISOCatastropheDefinition
Namespace Prefix:	uihc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Insurance Commissions and Fees, Flood Program

+ References

No definition available.

+ Details

Name:	uihc_InsuranceCommissionsAndFeesFloodProgram
Namespace Prefix:	uihc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Losses ceded under aggregate contract

+ References

No definition available.

+ Details

Name:	uihc_Lossescededunderaggregatecontract
Namespace Prefix:	uihc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Percentage of Flood Premiums Ceded

+ References

No definition available.

+ Details

Name:	uihc_PercentageOfFloodPremiumsCeded
Namespace Prefix:	uihc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of Gross Earned Premiums

+ References

No definition available.

+ Details

Name:	uihc_PercentageofGrossEarnedPremiums
Namespace Prefix:	uihc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of group equity

+ References

No definition available.

+ Details

Name:	uihc_Percentageofgroupequity
Namespace Prefix:	uihc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Quota Share Agreement, Cession Rate

+ References

No definition available.

+ Details

Name:	uihc_QuotaShareAgreementCessionRate
Namespace Prefix:	uihc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Reinsurance Multi-Year Limit

+ References

No definition available.

+ Details

Name:	uihc_ReinsuranceMultiYearLimit
Namespace Prefix:	uihc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Reinsurance Retention Policy, Coverage Percentage Hurricane Event

+ References

No definition available.

+ Details

Name:	uihc_ReinsuranceRetentionPolicyCoveragePercentageHurricaneEvent
Namespace Prefix:	uihc_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

Reinsurance Retention Policy, Number Of Private Reinsurers

+ References

No definition available.

+ Details

Name:	uihc_ReinsuranceRetentionPolicyNumberOfPrivateReinsurers
Namespace Prefix:	uihc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Reinsurance Retention Policy, Participation Rate

+ References

No definition available.

+ Details

Name:	uihc_ReinsuranceRetentionPolicyParticipationRate
Namespace Prefix:	uihc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The unexpired portion of premiums ceded on policies in force as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 340
-Section 25
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6485982&loc=d3e22818-158507

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 825
-Section 50
-Paragraph 1B
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=99380617&loc=SL75241803-196195

+ Details

Name:	us-gaap_PrepaidReinsurancePremiums
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of recovery (expense) related to provision for policy benefits and costs incurred for policies assumed and ceded.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 20
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=99397103&loc=d3e6811-158387

+ Details

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

- Definition

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

+ References

No definition available.

+ Details

Name:	us-gaap_ReinsuranceRetentionPolicyAmountRetained
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

Name:	us-gaap_ReinsuranceRetentionPolicyExcessRetentionAmountReinsured
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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

Name:	us-gaap_ReinsuranceRetentionPolicyLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	uihc_InsuranceProductLineAxis=us-gaap_CatastropheMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	uihc_ReinsuranceEventTypeAxis=uihc_FirstCatastrophicEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=stpr_FL
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	uihc_ReinsuranceEventTypeAxis=uihc_SecondCatastrophicEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	uihc_ReinsuranceEventTypeAxis=uihc_SecondAndSubsequentCatastrophicEventsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	uihc_ReinsuranceContractCounterpartyNameAxis=uihc_FloridaHurricaneCatastropheFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	uihc_ReinsuranceContractCounterpartyNameAxis=uihc_UnaffiliatedPrivateReinsurersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	uihc_InsuranceProductLineAxis=uihc_CATAggregateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	uihc_InsuranceProductLineAxis=uihc_CATBondMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Reinsurance (Details) $ in Thousands				3 Months Ended		9 Months Ended
Reinsurance (Details) $ in Thousands	Jun. 01, 2018 USD ($) Rate	Jan. 01, 2018 USD ($) Rate	Jun. 01, 2017 USD ($) catastrophic_event reinsurer	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($) Rate
Reinsurance Retention Policy
Quota Share Agreement, Cession Rate \| Rate								20.00%
Reinsurance Multi-Year Limit	$ 262,500
Prepaid reinsurance premiums				$ 319,916		$ 319,916		$ 201,904
Policyholder Benefits and Claims Incurred, Assumed and Ceded				66,278	$ 20,419	$ 340,316	$ 40,984
Flood premiums ceded (percentage)						100.00%
Insurance commissions and fees under Flood Program				$ 408	$ 308	$ 1,194	$ 905
Minimum
Reinsurance Retention Policy
ISO Catastrophe Definition			$ 25,000
Maximum
Reinsurance Retention Policy
Amount of risk reinsured in excess of stated retention	3,100,000
Catastrophe \| First Catastrophic Event
Reinsurance Retention Policy
Reinsurance Retention Policy, Coverage Percentage Hurricane Event \| catastrophic_event			0.010
Catastrophe \| First Catastrophic Event \| Maximum
Reinsurance Retention Policy
Stated amount of upper retention limit per policy	$ 25,000
Percentage of group equity \| Rate	4.60%
Catastrophe \| First Catastrophic Event \| FLORIDA \| Maximum
Reinsurance Retention Policy
Stated amount of upper retention limit per policy	$ 60,000
Percentage of group equity \| Rate	0.00%
Catastrophe \| Second Catastrophic Event
Reinsurance Retention Policy
Reinsurance Retention Policy, Coverage Percentage Hurricane Event \| catastrophic_event			0.020
Catastrophe \| Second And Subsequent Catastrophic Events \| Maximum
Reinsurance Retention Policy
Stated amount of upper retention limit per policy	$ 25,000
Catastrophe \| Florida Hurricane Catastrophe Fund \| FLORIDA
Reinsurance Retention Policy
Reinsurance Retention Policy, Participation Rate	45.00%
Aggregate Coverage for Covered Losses Under Reinsurance Contract	$ 907,000
Catastrophe \| Unaffiliated Private Reinsurers
Reinsurance Retention Policy
Number of private reinsurers \| reinsurer			41
CAT Aggregate
Reinsurance Retention Policy
Percentage of Gross Earned Premiums \| Rate		4.75%
Stated amount of upper retention limit per policy		$ 20,000
Losses ceded under aggregate contract						$ 20,000
CAT Bond
Reinsurance Retention Policy
Reinsurance Multi-Year Limit	$ 100,000