Guarantor and Non-Guarantor Financial Statements (Details)	3 Months Ended	9 Months Ended
Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Guarantor and Nonguarantor Financial Statements [Abstract]
Consolidated entity ownership percentage	100.00%	100.00%	100.00%	100.00%

Guarantor and Nonguarantor Financial Statements [Abstract]

No definition available.

Name:	kw_GuarantorAndNonguarantorFinancialStatementsAbstract
Namespace Prefix:	kw_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration