Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income (loss)		$ 5.1	$ (3.0)	$ 30.7	$ 110.6
Other comprehensive income (loss), net of tax:
Unrealized foreign currency translation loss		(51.8)	(89.0)	(88.0)	(67.1)
Unrealized (loss) gain on marketable securities		0.0	(1.1)	0.1	(1.1)
Amounts reclassified out of AOCI during the period		(0.3)	0.0	9.7	(7.1)
Unrealized currency derivative contracts (loss) gain		(8.3)	20.1	6.7	16.5
Total other comprehensive (loss) gain for the period		(60.4)	(70.0)	(71.5)	(58.8)
Comprehensive (loss) income		(55.3)	(73.0)	(40.8)	51.8
Comprehensive loss (income) attributable to noncontrolling interests	[1]	67.9	58.0	78.3	(23.5)
Comprehensive income (loss) attributable to Kennedy-Wilson Holdings, Inc. common shareholders		$ 12.6	$ (15.0)	$ 37.5	$ 28.3

[1] Comprehensive income attributable to noncontrolling interest includes allocation of unrealized currency translation losses and currency derivative contracts.