KW Unsecured Debt - Schedule of Unsecured Debt (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
KW Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt (excluding loan fees)	$ 1,146.3	$ 1,146.1
Unamortized loan fees	(17.7)	(14.4)
Total debt	1,128.6	1,131.7
Unamortized discount (premium)	(3.7)	(3.9)
Line of Credit [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt (excluding loan fees)	0.0	0.0
Senior Notes [Member]
Debt Instrument [Line Items]
Debt (excluding loan fees)	$ 1,146.3	$ 1,146.1

Long-Term Debt, Net of (Premium) Discount

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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Amount, after accumulated amortization, of debt discount (premium).

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- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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