Equity Method Investment, Ownership Percentage Sold

No definition available.

Name:	kw_EquityMethodInvestmentOwnershipPercentageSold
Namespace Prefix:	kw_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Number Of Assets In Real Estate Joint Venture

+ References

No definition available.

+ Details

Name:	kw_NumberOfAssetsInRealEstateJointVenture
Namespace Prefix:	kw_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Real Estate Units Sold, Number Of Assets

+ References

No definition available.

+ Details

Name:	kw_RealEstateUnitsSoldNumberOfAssets
Namespace Prefix:	kw_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Area of a real estate property.

+ References

No definition available.

+ Details

Name:	us-gaap_AreaOfRealEstateProperty
Namespace Prefix:	us-gaap_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of gain (loss) from deconsolidation of subsidiary and derecognition of group of assets constituting transfer of business or nonprofit activity, excluding conveyance of oil and gas mineral rights and transfer of good or service in contract with customer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109239629&loc=SL4582445-111684

+ Details

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

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

+ Details

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of units in a real estate property owned as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfUnitsInRealEstateProperty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
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_RealEstateLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=kw_AxaJointVentureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=kw_AXAInvestmentManagersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=kw_KennedyWilsonHoldingsInc.AndAXSInvestmentManagersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=srt_MultifamilyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

REAL ESTATE AND ACQUIRED IN PLACE LEASE VALUE - Deconsolidation of Previously Consolidated Real Estate (Details) ft² in Thousands, $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Jan. 31, 2020	Dec. 31, 2019 USD ($) ft² asset property_unit	Dec. 31, 2019 USD ($) ft² asset property_unit	Dec. 31, 2018 USD ($)
Real Estate [Line Items]
Real estate units sold, number of assets \| asset		2	2
Ownership percentage sold of equity method investment		20.00%
Deconsolidation, gain (loss)		$ 112.4
Subsequent Event [Member]
Real Estate [Line Items]
Ownership percentage sold of equity method investment	30.00%
Axa Joint Venture [Member]
Real Estate [Line Items]
Equity method investment, ownership percentage		80.00%	80.00%
Ownership percentage sold of equity method investment			20.00%
Deconsolidation, gain (loss)			$ 212.4	$ 102.7
Axa Joint Venture [Member] \| AXA Investment Managers [Member]
Real Estate [Line Items]
Equity method investment, ownership percentage		50.00%	50.00%
Axa Joint Venture [Member] \| Kennedy Wilson Holdings, Inc. and AXS Investment Managers [Member]
Real Estate [Line Items]
Deconsolidation, gain (loss)			$ 317.8	$ 169.5
Axa Joint Venture [Member] \| Multifamily [Member]
Real Estate [Line Items]
Number of units \| property_unit		2,270	2,270
Area of real estate property (in sq ft) \| ft²		391	391
Number of assets \| property_unit		12	12
Equity method investment, ownership percentage		80.00%	80.00%
Ownership percentage sold of equity method investment			20.00%