Schedule IV - Mortgage Loans on Real Estate (Mortgage Loans on Real Estate Activity) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2013
Movement in Mortgage Loans on Real Estate [Roll Forward]
Balance - December 31, 2012	$ 230.7
New mortgage loans	112.5
Other additions	141.6
Amortization of mortgage premium	(0.7)
Payments of principal	(1.7)
Foreclosures	0
Loan loss reserve	0
Other deductions	(80.6)
Balance - December 31, 2013	$ 401.8

Mortgage Loans on Real Estate, Loan Loss Reserve

No definition available.

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

- Definition

Total carrying amount of mortgage loans as of the balance sheet date.

+ 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 SEC

-Name Regulation S-X (SX)

-Number 210

-Section 29

-Article 12

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 FASB

-Name Accounting Standards Codification

-Topic 948

-SubTopic 310

-Section S99

-Paragraph 1

-Subparagraph (SX 210.12-29.6)

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

+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

The amount of premium on mortgage loans on real estate amortized during the reporting period.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of principal collected on mortgage loans on real estate during the reporting period.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of mortgage loans on real estate which were foreclosed on during the reporting period.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Total amount of new mortgage loans on real estate during the reporting period.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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- Definition

Total amount of additions to mortgage loans other than new loans during the reporting period.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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- Definition

The amount of reductions in principal on mortgage loans other than foreclosures, costs of mortgages sold, and amortization of premium during the reporting period.

+ References

+ Details

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