Investments - Cost or Amortized Cost and Fair Value of Securities Available for Sale (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Schedule Of Available For Sale Securities [Line Items]
Cost or Amortized Cost	$ 489,846	$ 426,568
Gross Unrealized Gains	693	514
Gross Unrealized Losses	(7,221)	(3,501)
Fair Value	483,318	423,581
Short-term Investments [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost or Amortized Cost	25,011	50,000
Gross Unrealized Gains	10
Gross Unrealized Losses		(10)
Fair Value	25,021	49,990
U.S. Government Obligations and Agencies [Member] \| Fixed Maturities [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost or Amortized Cost	126,209	120,627
Gross Unrealized Gains		38
Gross Unrealized Losses	(867)	(627)
Fair Value	125,342	120,038
Corporate Bonds [Member] \| Fixed Maturities [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost or Amortized Cost	126,421	120,025
Gross Unrealized Gains	137	171
Gross Unrealized Losses	(1,041)	(364)
Fair Value	125,517	119,832
Mortgage-Backed and Asset-Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost or Amortized Cost	151,328	107,589
Fair Value	150,160	107,223
Mortgage-Backed and Asset-Backed Securities [Member] \| Fixed Maturities [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost or Amortized Cost	151,328	107,589
Gross Unrealized Gains	97	136
Gross Unrealized Losses	(1,265)	(502)
Fair Value	150,160	107,223
Redeemable Preferred Stock [Member] \| Fixed Maturities [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost or Amortized Cost	9,665	6,700
Gross Unrealized Gains	429	165
Gross Unrealized Losses	(29)	(9)
Fair Value	10,065	6,856
Other [Member] \| Fixed Maturities [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost or Amortized Cost	5,000
Gross Unrealized Losses	(1)
Fair Value	4,999
Common Stock [Member] \| Equity Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost or Amortized Cost	10,991	331
Gross Unrealized Gains	15	4
Gross Unrealized Losses	(244)	(65)
Fair Value	10,762	270
Mutual Funds [Member] \| Equity Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost or Amortized Cost	35,221	21,296
Gross Unrealized Gains	5
Gross Unrealized Losses	(3,774)	(1,924)
Fair Value	$ 31,452	$ 19,372

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 25
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=51813488&loc=d3e22054-111558

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49167202&loc=d3e26610-111562

+ Details

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

- Definition

Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563

+ Details

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

- Definition

Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563

+ Details

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

- Definition

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.2)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

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

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_ShortTermInvestmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_FixedMaturitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=uve_MortgageBackedAndAssetBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_RedeemablePreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_OtherDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_CommonStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_EquitySecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=uve_MutualFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: