Business Combination, Equity Interest in Acquiree

No definition available.

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- Definition

Initial Public Offering, Contribution of Interest Percentage in Portfolio

+ References

No definition available.

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- Definition

This element represents the fair value of the noncontrolling interest in the acquiree at the acquisition date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (e)(1)
-URI http://asc.fasb.org/extlink&oid=73530397&loc=d3e4845-128472

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- Definition

Amount of facility held for productive use including, but not limited to, office, production, storage and distribution facilities, acquired at the acquisition date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=73530397&loc=d3e4845-128472

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- Definition

The amount of financial liabilities assumed (as defined) which have been recognized as of the acquisition date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financial Liability
-URI http://asc.fasb.org/extlink&oid=6513127

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 55
-Paragraph 37
-URI http://asc.fasb.org/extlink&oid=73531372&loc=d3e2207-128464

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=73530397&loc=d3e4845-128472

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- Definition

The amount of identifiable intangible assets recognized as of the acquisition date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 55
-Paragraph 37
-URI http://asc.fasb.org/extlink&oid=73531372&loc=d3e2207-128464

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=73530397&loc=d3e4845-128472

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Balance Type:	debit
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- Definition

Amount of real estate acquired, at the acquisition date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=73530397&loc=d3e4845-128472

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- References

No definition available.

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- Definition

In a business combination achieved in stages, this element represents the amount of gain recognized by the entity as a result of remeasuring to fair value the equity interest in the acquiree it held before the business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (g)(2)
-URI http://asc.fasb.org/extlink&oid=65885119&loc=d3e1392-128463

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- Definition

The difference between the carrying value and the sale price of real estate or properties that were intended to be sold or held for capital appreciation or rental income. This element refers to the gain (loss) included in earnings and not to the cash proceeds of the sale. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585

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- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

+ References

No definition available.

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REAL ESTATE AND ACQUIRED IN PLACE LEASE VALUE - Schedule of Acquisitions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Feb. 28, 2014
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Land	$ 195.8	$ 499.3
Building	550.6	973.9
Acquired in place lease values	32.8	163.2
Investment debt	295.8	584.3
Noncontrolling interests	227.0	849.5
KWH Shareholders' Equity	256.4	202.6
Gain on sale of real estate properties	137.9	73.5	$ 7.7
Acquisition-related gains	$ 16.2	$ 108.1	218.1
KWE [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Ownership percentage by parent	23.60%	18.20%
Gain on sale of real estate properties	$ 90.0	$ 37.5	$ 0.6
Interest contributed as part of initial public offering				50.00%
Retail, Multi-Family and Residential Acquired in Western U.S. [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Land	124.6
Building	360.2
Acquired in place lease values	8.7
Investment debt	295.8
Noncontrolling interests	2.0
KWH Shareholders' Equity	195.7
Gain on sale of real estate properties	8.6
Acquisition-related gains	7.6
Properties Acquired in Ireland [Member] \| KWE [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Land	25.3
Building	84.9
Acquired in place lease values	5.8
Investment debt	0.0
Noncontrolling interests	91.6
KWH Shareholders' Equity	24.4
Properties Acquired in Spain [Member] \| KWE [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Land	1.9
Building	17.1
Acquired in place lease values	0.3
Investment debt	0.0
Noncontrolling interests	15.3
KWH Shareholders' Equity	$ 4.0
Commercial and Multifamily Acquired in Western U.S. [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Land		16.7
Building		56.0
Acquired in place lease values		1.5
Investment debt		55.0
Noncontrolling interests		0.5
KWH Shareholders' Equity		18.7
Commercial, Retail and Industrial Properties Acquired in United Kingdom [Member] \| KWE [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Land		276.1
Building		421.7
Acquired in place lease values		76.6
Investment debt		529.3
Noncontrolling interests		205.7
KWH Shareholders' Equity		39.4
Commercial Portfolio Acquired in United Kingdom [Member] \| KWE [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Land		104.4
Building		178.7
Acquired in place lease values		45.4
Investment debt		0.0
Noncontrolling interests		270.4
KWH Shareholders' Equity		58.1
Commercial Office Buildings Acquired in Dublin [Member] \| KWE [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Land		3.9
Building		26.3
Acquired in place lease values		2.8
Investment debt		0.0
Noncontrolling interests		22.6
KWH Shareholders' Equity		10.4
Development Projects Acquired in Spain [Member] \| KWE [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Land		0.0
Building		43.9
Acquired in place lease values		0.0
Investment debt		0.0
Noncontrolling interests		36.8
KWH Shareholders' Equity		7.1
Supermarkets and Shopping Center Acquired in Spain [Member] \| KWE [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Land		50.7
Building		112.2
Acquired in place lease values		8.8
Investment debt		0.0
Noncontrolling interests		141.0
KWH Shareholders' Equity		30.7
Commercial Portfolio Acquired in Italy [Member] \| KWE [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Land		47.5
Building		135.1
Acquired in place lease values		28.1
Investment debt		0.0
Noncontrolling interests		172.5
KWH Shareholders' Equity		38.2
Real Estate Acquired in Spain and Italy [Member] \| KWE [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Acquisition-related gains		$ 7.8
KWE [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Ownership percentage by parent	23.60%
KWE [Member] \| Commercial Acquired in United Kingdom [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Land	$ 44.0
Building	88.4
Acquired in place lease values	18.0
Investment debt	0.0
Noncontrolling interests	118.1
KWH Shareholders' Equity	$ 32.3