Equity Method Investment, Number of Investments Amended

No definition available.

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

- Definition

Equity Method Investment, Number of Properties in Portfolio

+ References

No definition available.

+ Details

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

- Definition

Equity Method Investments, Number of Units in Portfolio

+ References

No definition available.

+ Details

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

- Definition

Equity Method Investments, Number with Unfulfilled Capital Commitments

+ References

No definition available.

+ Details

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

- Definition

Equity Method Investments, Unfulfilled Capital Commitments

+ References

No definition available.

+ Details

Name:	kw_EquityMethodInvestmentsUnfulfilledCapitalCommitments
Namespace Prefix:	kw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Guarantor Obligations, Maximum Exposure, Undiscounted, Percentage of Property Level Debt

+ References

No definition available.

+ Details

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

- Definition

Participating interests in loan pools acquired with deteriorated credit quality

+ References

No definition available.

+ Details

Name:	kw_InvestmentInLoanPoolParticipations
Namespace Prefix:	kw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Noncash Contributions and Payments to Acquire Equity Method Investments

+ References

No definition available.

+ Details

Name:	kw_NoncashContributionsandPaymentstoAcquireEquityMethodInvestments
Namespace Prefix:	kw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Proceeds from Equity Method Investments, Dividends and Distributions, Operating and Investing

+ References

No definition available.

+ Details

Name:	kw_ProceedsFromEquityMethodInvestmentsDividendsAndDistributionsOperatingAndInvesting
Namespace Prefix:	kw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Variable Interest Entity, Number Of Investments

+ References

No definition available.

+ Details

Name:	kw_VariableInterestEntityNumberOfInvestments
Namespace Prefix:	kw_
Data Type:	xbrli:integerItemType
Balance Type:	na
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://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

+ Details

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

- Definition

This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

+ 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 210.5-02.12)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=16385135&loc=d3e33749-111570

+ Details

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

- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 460

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph (b)(1)

-URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248

+ Details

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

- Definition

Total investments in (A) an entity in which the entity has significant influence, but does not have control, (B) subsidiaries that are not required to be consolidated and are accounted for using the equity and or cost method, and (C) an entity in which the reporting entity shares control of the entity with another party or group. Includes long-term advances receivable from a party that is affiliated with the reporting entity by means of direct or indirect ownership.

+ References

+ Details

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

- Definition

Amount before tax, after reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e637-108580

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 10A

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=28358780&loc=SL7669646-108580

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 830

-SubTopic 20

-Section 35

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6939497&loc=d3e30304-110892

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 830

-SubTopic 30

-Section 45

-Paragraph 20

-Subparagraph (b,d)

-URI http://asc.fasb.org/extlink&oid=6915805&loc=d3e32211-110900

+ Details

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

- Definition

The cash outflow associated with the investment in or advances to an entity in which the reporting entity shares control of the entity with another party or group.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 13

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3213-108585

+ Details

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

- Details

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

- Definition

The reporting entity's maximum amount of exposure to loss as a result of its involvement with the Variable Interest Entity (VIE).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph b

-URI http://asc.fasb.org/extlink&oid=28200181&loc=d3e5728-111685

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=28200181&loc=d3e5747-111685

+ Details

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

- Definition

Carrying amount of the assets in the reporting entity's statement of financial position that relate to the reporting entity's variable interest in the Variable Interest Entity (VIE), where the reporting entity is not the VIE's primary beneficiary.

+ References

+ Details

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

- Details

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

Unconsolidated Investments (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended				6 Months Ended				3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014 JointVenture	Jun. 30, 2013	Dec. 31, 2013	Jun. 30, 2014 Performance Guarantee [Member] Loans Payable [Member]	Jun. 30, 2014 Variable Interest Entity, Not Primary Beneficiary [Member] VariableInterestEntity	Jun. 30, 2014 Minimum [Member]	Jun. 30, 2014 Maximum [Member]	Mar. 31, 2014 Europe [Member] Investment	Jun. 30, 2014 KW Residential, LLC [Member] apartment_unit ApartmentBuildling	Jun. 30, 2013 KW Residential, LLC [Member]	Jun. 30, 2014 KW Residential, LLC [Member] apartment_unit ApartmentBuildling	Jun. 30, 2013 KW Residential, LLC [Member]	Dec. 31, 2013 KW Residential, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage								5.00%	50.00%		41.00%		41.00%
Investments in joint ventures	$ 473.3		$ 473.3		$ 751.4
Number of properties in portfolio											50		50
Number of units in portfolio											2,400		2,400
Unconsolidated investments	532.2		532.2		786.1										68.8
Foreign currency exchange gain (loss)	0.2	(1.1)	0.4	(5.0)							0.6	(2.0)	(0.4)	(6.3)
Equity method investment, number of investments amended										6
Payments to acquire equity method investment			(80.9)
Contributions to acquire interest in joint venture			19.7
Proceeds from equity method investments			100.3								1.3	5.1	1.7	18.6
Variable Interest Entity, Not Primary Beneficiary, Disclosures [Abstract]
Variable interest entity, number of investments							5
Variable interest entity, carrying amount assets							170.5
Variable interest entity, maximum loss exposure							72.9
Unfulfilled capital commitments			11.3
Unfulfilled capital commitments, number with unfulfilled capital commitments			4
Guarantor obligations, maximum exposure						63.8
Guarantor obligations, maximum exposure, percentage of property level debt						2.00%
Investments in loan pool participations	$ 58.9		$ 58.9		$ 34.7