Unconsolidated Investments (Schedule of Investments in Loan Pools) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2014		Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Initial Unpaid Principal Balance	$ 1,995.3	[1]
Unpaid Principal Balance	826.4	[1]
Kennedy Wilson Initial Equity Invested	119.2
Investment Balance at June 30, 2014	58.9		34.7
Expected Accretion Over Total Estimated Collection Period	25.6
Accreted to Date	13.5
February 2010 [Member] | U.S. Loan Pool 1 [Member] | Western United States [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Kennedy Wilson Ownership	15.00%	[2]
Initial Unpaid Principal Balance	342.4	[1],[2]
Unpaid Principal Balance		[1],[2]
Kennedy Wilson Initial Equity Invested	11.2	[2]
Investment Balance at June 30, 2014	0.6	[2]
Expected Accretion Over Total Estimated Collection Period	4.6	[2]
Accreted to Date	4.6	[2]
April 2012 [Member] | U.S. Loan Pool 2 [Member] | Western United States [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Kennedy Wilson Ownership	75.00%
Initial Unpaid Principal Balance	43.4	[1]
Unpaid Principal Balance	2.8	[1]
Kennedy Wilson Initial Equity Invested	30.9
Investment Balance at June 30, 2014	2.4
Expected Accretion Over Total Estimated Collection Period	4.3
Accreted to Date	4.0
August 2012 [Member] | Irish Loan Pool 1 [Member] | Ireland [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Kennedy Wilson Ownership	10.00%
Initial Unpaid Principal Balance	492.7	[1]
Unpaid Principal Balance	345.9	[1]
Kennedy Wilson Initial Equity Invested	7.0
Investment Balance at June 30, 2014	8.5
Expected Accretion Over Total Estimated Collection Period	1.9
Accreted to Date	0.8
December 2012 [Member] | UK Loan Pool 1 [Member] | United Kingdom [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Kennedy Wilson Ownership	5.00%
Initial Unpaid Principal Balance	661.9	[1]
Unpaid Principal Balance	110.2	[1]
Kennedy Wilson Initial Equity Invested	19.3
Investment Balance at June 30, 2014	2.7
Expected Accretion Over Total Estimated Collection Period	2.0
Accreted to Date	1.6
April 2013 [Member] | UK Loan Pool 3 [Member] | United Kingdom [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Kennedy Wilson Ownership	10.00%
Initial Unpaid Principal Balance	198.4	[1]
Unpaid Principal Balance	111.0	[1]
Kennedy Wilson Initial Equity Invested	13.0
Investment Balance at June 30, 2014	5.6
Expected Accretion Over Total Estimated Collection Period	5.6
Accreted to Date	1.2
August 2013 [Member] | UK Loan Pool 3 [Member] | United Kingdom [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Kennedy Wilson Ownership	20.00%
Initial Unpaid Principal Balance	145.5	[1]
Unpaid Principal Balance	145.5	[1]
Kennedy Wilson Initial Equity Invested	7.5
Investment Balance at June 30, 2014	8.7
Expected Accretion Over Total Estimated Collection Period	4.9
Accreted to Date	1.2
May 2014 [Member] | UK Loan Pool 4 [Member] | United Kingdom [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Kennedy Wilson Ownership	33.30%
Initial Unpaid Principal Balance	111.0	[1]
Unpaid Principal Balance	111.0	[1]
Kennedy Wilson Initial Equity Invested	30.3
Investment Balance at June 30, 2014	30.4
Expected Accretion Over Total Estimated Collection Period	2.3
Accreted to Date	$ 0.1
United Kingdom, Pounds
Accounts, Notes, Loans and Financing Receivable [Line Items]
Foreign currency exchange rate	0.59
Euro Member Countries, Euro
Accounts, Notes, Loans and Financing Receivable [Line Items]
Foreign currency exchange rate	0.73

[1] Estimated foreign exchange rate is £0.59 = $1 USD and €0.73 = $1 USD as of June 30, 2014.

[2] Equity invested represents guarantee claims against note holders in loan pool.