Investments - Schedule of Estimated Fair Values and Gross Unrealized Losses (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Less than 12 months
Fair Value	$ 358.8	$ 2,086.6
Unrealized Losses	(5.8)	(105.1)
12 months or greater
Fair Value	441.6	271.4
Unrealized Losses	(27.6)	(12.3)
Fair Value	800.4	2,358.0
Unrealized Losses	(33.4)	(117.4)
U.S. Government and government agencies
Less than 12 months
Fair Value	0.3	5.0
Unrealized Losses	0.0	0.0
12 months or greater
Fair Value	0.0	3.3
Unrealized Losses	0.0	0.0
Fair Value	0.3	8.3
Unrealized Losses	0.0	0.0
States, municipalities and political subdivisions
Less than 12 months
Fair Value	2.0	117.2
Unrealized Losses	0.0	(1.3)
12 months or greater
Fair Value	0.0	1.9
Unrealized Losses	0.0	(0.1)
Fair Value	2.0	119.1
Unrealized Losses	0.0	(1.4)
Residential mortgage-backed securities
Less than 12 months
Fair Value	2.3	22.4
Unrealized Losses	0.0	(1.2)
12 months or greater
Fair Value	8.2	5.7
Unrealized Losses	(0.6)	(0.1)
Fair Value	10.5	28.1
Unrealized Losses	(0.6)	(1.3)
Commercial mortgage-backed securities
Less than 12 months
Fair Value	58.1	57.8
Unrealized Losses	(0.6)	(1.1)
12 months or greater
Fair Value	0.2	0.0
Unrealized Losses	0.0	0.0
Fair Value	58.3	57.8
Unrealized Losses	(0.6)	(1.1)
Asset-backed securities
Less than 12 months
Fair Value	126.5	466.0
Unrealized Losses	(1.5)	(29.6)
12 months or greater
Fair Value	255.8	5.9
Unrealized Losses	(15.5)	(0.5)
Fair Value	382.3	471.9
Unrealized Losses	(17.0)	(30.1)
Corporate and other
Less than 12 months
Fair Value	169.6	1,418.2
Unrealized Losses	(3.7)	(71.9)
12 months or greater
Fair Value	177.4	254.6
Unrealized Losses	(11.5)	(11.6)
Fair Value	347.0	1,672.8
Unrealized Losses	$ (15.2)	$ (83.5)

Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months

No definition available.

Name:	hchc_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAbstract
Namespace Prefix:	hchc_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, More than 12 Months [Abstract]

+ References

No definition available.

+ Details

Name:	hchc_DebtSecuritiesAvailableforsaleContinuousUnrealizedLossPositionMorethan12MonthsAbstract
Namespace Prefix:	hchc_
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 other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118955579&loc=SL82922890-210455

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27337-111563

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=118942371&loc=SL82922954-210456

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27337-111563

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118955579&loc=SL82922890-210455

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=118942371&loc=SL82922954-210456

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position without allowance for credit loss.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27290-111563

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
-Paragraph 4
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=118955579&loc=SL82922888-210455

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=118942371&loc=SL82922954-210456

+ Details

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

- Definition

Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

+ Details

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

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USStatesAndPoliticalSubdivisionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_ResidentialMortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CommercialMortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=hchc_CorporateDebtSecuritiesandOtherMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: