Real Estate and In-Place Lease Value - Schedule of Pro Forma Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Real Estate [Abstract]
Pro forma revenues	$ 479.9	$ 163.5	$ 363.4	$ 149.3
Pro forma net income (loss) attributable to Kennedy-Wilson Holdings, Inc. common shareholders	$ 45.1	$ 14.6	$ 52.8	$ 0.5
Pro forma net income (loss) per share:
Basic (in dollars per share)	$ 0.13	$ 0.00	$ 0.43	$ 0.50
Diluted (in dollars per share)	$ 0.13	$ 0.00	$ 0.42	$ 0.49

The pro forma basic net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(2)-(3)

-URI http://asc.fasb.org/extlink&oid=56956515&loc=d3e1392-128463

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The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

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The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

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