UNAUDITED QUARTERLY INFORMATION (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 29.6	$ 33.2	$ 36.0	$ 22.4	$ 23.0	$ 15.2	$ 14.1	$ 11.8	$ 121.2	$ 64.1	$ 62.6
Operating expenses	44.0	37.3	40.1	27.6	36.9	20.8	18.4	15.4	149.1	91.5	66.1
Equity in joint venture income	8.8	9.4	11.9	(0.3)	9.1	1.8	5.1	5.5	28.8	13.7	9.1
Interest income from loan pool participations and notes receivable	3.3	4.0	3.3	2.9	2.1	3.7	2.9	0.5	13.5	9.2	8.0
Operating income	(2.3)	9.3	11.1	(2.6)	(2.7)	(0.1)	3.7	2.4	15.4	3.3	17.0
Non-operating (expenses) income	27.2	(11.3)	(12.9)	(1.9)	17.9	(6.5)	(5.8)	(2.2)
Income from continuing operations before benefit from (provision for) income taxes	24.9	(2.0)	(1.8)	(4.5)	15.2	(6.6)	(2.1)	0.2	16.5	6.7	5.1
(Provision for) benefit from income taxes	(4.3)	(0.8)	0.5	1.7	(4.9)	2.5	1.1	1.5	(2.9)	0.2	2.0
Income from continuing operations	20.6	(2.8)	(1.3)	(2.8)	10.3	(4.1)	(1.0)	1.7	13.6	6.9	7.1
Loss from discontinued operations, net of income taxes		(0.3)							(0.3)
Gain (loss) from sale of real estate, net of income taxes		0.4		0.2				(0.2)	0.6	(0.2)	0.4
Net income	20.6	(2.7)	(1.3)	(2.6)	10.3	(4.1)	(1.0)	1.5	13.9	6.7	7.5
Net (income) attributable to the noncontrolling interests	(22.9)	0.7	0.9	1.0	0.5	(0.1)	(0.1)	(2.8)	(20.3)	(2.5)	(1.2)
Net (loss) income attributable to Kennedy-Wilson Holdings, Inc.	(2.3)	(2.0)	(0.4)	(1.6)	10.8	(4.2)	(1.1)	(1.3)	(6.4)	4.2	6.3
Preferred stock dividends and accretion of issuance costs	(2.0)	(2.1)	(2.1)	(2.0)	(2.0)	(2.0)	(2.1)	(2.0)	(8.1)	(8.1)	(8.7)
Net loss attributable to Kennedy-Wilson Holdings, Inc. common shareholders	$ (4.3)	$ (4.1)	$ (2.5)	$ (3.6)	$ 8.8	$ (6.2)	$ (3.2)	$ (3.3)	$ (14.5)	$ (3.9)	$ (2.4)
Basic (loss) earnings per share (in dollars per share)	$ (0.05)	$ (0.06)	$ (0.03)	$ (0.06)	$ 0.15	$ (0.11)	$ (0.06)	$ (0.07)
Diluted (loss) earnings per share (in dollars per share)	$ (0.05)	$ (0.06)	$ (0.03)	$ (0.06)	$ 0.15	$ (0.11)	$ (0.06)	$ (0.07)