Loan Conversion, Ownership Percentage Obtained

No definition available.

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Namespace Prefix:	kw_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of properties securing loans

+ References

No definition available.

+ Details

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

- Definition

Noncash or Part Noncash Acquisition, Fixed Asset Acquired, Square Foot

+ References

No definition available.

+ Details

Name:	kw_NoncashorPartNoncashAcquisitionFixedAssetAcquiredSquareFoot
Namespace Prefix:	kw_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of Acre Lot Acquired by Foreclosure

+ References

No definition available.

+ Details

Name:	kw_NumberofAcreLotAcquiredbyForeclosure
Namespace Prefix:	kw_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of Related-Party Funds Paid Off

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_AccountsNotesAndLoansReceivableLineItems
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

For receivables acquired in a business combination, excluding certain loans and debt securities acquired in a transfer (as defined), this element represents the fair value of the receivables acquired, by major class of receivable, such as loans, direct finance leases (as defined), and any other class of receivables.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)(1)

-URI http://asc.fasb.org/extlink&oid=39739317&loc=d3e4845-128472

+ Details

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

- Definition

For receivables acquired in a business combination, excluding certain loans and debt securities acquired in a transfer (as defined), this element represents the gross contractual amounts receivable, by major class of receivable, such as loans, direct finance leases (as defined), and any other class of receivables.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)(2)

-URI http://asc.fasb.org/extlink&oid=39739317&loc=d3e4845-128472

+ Details

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

- Definition

Interest and fee income generated by loans the Entity intends and has the ability to hold for the foreseeable future, or until maturity or payoff, including commercial and consumer loans, whether domestic or foreign, which may consist of: (1) industrial and agricultural; (2) real estate; and (3) real estate construction loans; (4) trade financing; (5) lease financing; (6) home equity lines-of-credit; (7) automobile and other vehicle loans; and (8) credit card and other revolving-type loans. Also includes interest income for leases held by the Entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.1)

-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 1

-Article 9

+ Details

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

- Definition

Indicates the number of mortgages under each classification.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 205

-SubTopic 10

-Section S99

-Paragraph 6

-Subparagraph (SX 210.5-04.(c) Schedule IV)

-URI http://asc.fasb.org/extlink&oid=27047687&loc=d3e5864-122674

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 948

-SubTopic 310

-Section S99

-Paragraph 1

-Subparagraph (SX 210.12-29.3)

-URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph c

-Subparagraph Schedule IV

-Article 5

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 29

-Paragraph 3

-Article 12

+ Details

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

- Details

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- Details

Name:	us-gaap_BusinessAcquisitionAxis=kw_HotelAcquiredinIrelandMember
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Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=kw_RetailAcquiredinCaliforniaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=kw_VacantLotAcquiredinCaliforniaMember
Namespace Prefix:
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Period Type:

LOANS (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended			3 Months Ended	6 Months Ended	3 Months Ended
	Sep. 30, 2014 Loan	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2014 sqft	Jun. 30, 2014 Loan Property	Jun. 30, 2014 Property
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of related-party funds paid off	2kw_NumberofRelatedPartyFundsPaidOff
Loans and other income		$ 16.8	$ 1.6	$ 2.8
Hotel Acquired in Ireland [Member] \| Notes Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross amount of acquired receivables					152.4
Ownership interest conversion percentage	100.00%
Retail Acquired in California [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Square footage of acquired office portfolio		133,000			133,000
Loan balance of acquired receivable					30.4
Vacant Lot Acquired in California [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acres in lot acquired by foreclosure		2.4			2.4
Kennedy Wilson Europe Real Estate, Pllc [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of properties securing loans	13
Kennedy Wilson Europe Real Estate, Pllc [Member] \| High Tech Properties in England [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of mortgage loans on real estate						5
Number of properties securing loans						5
Kennedy Wilson Europe Real Estate, Pllc [Member] \| High Tech Properties in England [Member] \| Notes Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross amount of acquired receivables						156.3	156.3
Loan balance of acquired receivable		146.1
Kennedy Wilson Europe Real Estate, Pllc [Member] \| Commercial Properties in England and Scotland [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of properties securing loans							20
Kennedy Wilson Europe Real Estate, Pllc [Member] \| Commercial Properties in England and Scotland [Member] \| Notes Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross amount of acquired receivables						62.2	62.2
Kennedy Wilson Europe Real Estate, Pllc [Member] \| Ireland Properties Acquired [Member] \| Notes Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross amount of acquired receivables	97.0
Loan balance of acquired receivable		92.4
Kennedy Wilson Europe Real Estate, Pllc [Member] \| Office Building Acquired in Dublin, Ireland [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross amount of acquired receivables		53.0
Kennedy Wilson Europe Real Estate, Pllc [Member] \| Class A Office Building Acquired in Burbank, CA [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross amount of acquired receivables		$ 5.0