Investment, Lockup, Minimum Notice Period

No definition available.

Name:	ufcs_InvestmentLockupMinimumNoticePeriod
Namespace Prefix:	ufcs_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Investment, Lockup Period

+ References

No definition available.

+ Details

Name:	ufcs_InvestmentLockupPeriod
Namespace Prefix:	ufcs_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Investment, Number Of Repurchase Dates

+ References

No definition available.

+ Details

Name:	ufcs_InvestmentNumberOfRepurchaseDates
Namespace Prefix:	ufcs_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Limited Liability Partnership Investment Fund, Fair Value Disclosure

+ References

No definition available.

+ Details

Name:	ufcs_LimitedLiabilityPartnershipInvestmentFundFairValueDisclosure
Namespace Prefix:	ufcs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of contractual obligation, including but not limited to, long-term debt, capital lease obligations, operating lease obligations, purchase obligations, and other commitments.

+ References

No definition available.

+ Details

Name:	us-gaap_ContractualObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of realized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27357-111563

+ Details

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

- Definition

The cash outflow associated with the acquisition of or advances to an entity that is related to it but not strictly controlled (for example, an unconsolidated subsidiary, affiliate, and joint venture or equity method investment) or the acquisition of an additional interest in a subsidiary (controlled entity).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3213-108585

+ Details

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

- Definition

Amount of cash inflow from sale of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=121553693&loc=d3e26853-111562

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3151-108585

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3179-108585

+ Details

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

- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in net income (trading) and investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.4)
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

+ Details

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

- Details

Name:	us-gaap_StatementOperatingActivitiesSegmentAxis=us-gaap_SegmentDiscontinuedOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

SUMMARY OF INVESTMENTS (Narrative) (Details)	1 Months Ended	12 Months Ended
SUMMARY OF INVESTMENTS (Narrative) (Details)	Dec. 31, 2019 USD ($) date	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Gain (Loss) on Securities [Line Items]
Proceeds from sale of available-for-sale investments		$ 50,744,000	$ 41,760,000	$ 132,250,000
Gross realized gains (losses)			0	0
Trading securities	$ 15,256,000	0	15,256,000
Remaining potential contractual obligation		8,484,000
Investment in limited liability partnership investment fund	$ 25,000,000
Lockup period	3 years
Minimum notice period	60 days
Number of possible repurchase dates \| date	4
Investment fair value		24,867,000
Discontinued Operations
Gain (Loss) on Securities [Line Items]
Proceeds from sale of available-for-sale investments		0	$ 0	$ 0
Gross realized gains (losses)		$ 0