Unconsolidated Investments (Cash Distributions by Investment Type and Location) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014
Schedule of Equity Method Investments [Line Items]
Operating distributions from unconsolidated investments	$ 8.5
Distributions from unconsolidated investments	8.8
Multifamily [Member]
Schedule of Equity Method Investments [Line Items]
Operating distributions from unconsolidated investments	2.7
Distributions from unconsolidated investments	1.5
Commercial [Member]
Schedule of Equity Method Investments [Line Items]
Operating distributions from unconsolidated investments	5.0
Distributions from unconsolidated investments	4.4
Residential [Member]
Schedule of Equity Method Investments [Line Items]
Operating distributions from unconsolidated investments	0.8
Distributions from unconsolidated investments	2.9
Western United States [Member]
Schedule of Equity Method Investments [Line Items]
Operating distributions from unconsolidated investments	4.6
Distributions from unconsolidated investments	3.4
Western United States [Member] | Multifamily [Member]
Schedule of Equity Method Investments [Line Items]
Operating distributions from unconsolidated investments	2.3
Distributions from unconsolidated investments	1.5
Western United States [Member] | Commercial [Member]
Schedule of Equity Method Investments [Line Items]
Operating distributions from unconsolidated investments	1.5
Distributions from unconsolidated investments	0
Western United States [Member] | Residential [Member]
Schedule of Equity Method Investments [Line Items]
Operating distributions from unconsolidated investments	0.8
Distributions from unconsolidated investments	1.9
Japan [Member]
Schedule of Equity Method Investments [Line Items]
Operating distributions from unconsolidated investments	0.4
Distributions from unconsolidated investments	0
Japan [Member] | Multifamily [Member]
Schedule of Equity Method Investments [Line Items]
Operating distributions from unconsolidated investments	0.4
Distributions from unconsolidated investments	0
Japan [Member] | Commercial [Member]
Schedule of Equity Method Investments [Line Items]
Operating distributions from unconsolidated investments	0
Distributions from unconsolidated investments	0
Japan [Member] | Residential [Member]
Schedule of Equity Method Investments [Line Items]
Operating distributions from unconsolidated investments	0
Distributions from unconsolidated investments	0
United Kingdom [Member]
Schedule of Equity Method Investments [Line Items]
Operating distributions from unconsolidated investments	2.3
Distributions from unconsolidated investments	4.4
United Kingdom [Member] | Multifamily [Member]
Schedule of Equity Method Investments [Line Items]
Operating distributions from unconsolidated investments	0
Distributions from unconsolidated investments	0
United Kingdom [Member] | Commercial [Member]
Schedule of Equity Method Investments [Line Items]
Operating distributions from unconsolidated investments	2.3
Distributions from unconsolidated investments	4.4
United Kingdom [Member] | Residential [Member]
Schedule of Equity Method Investments [Line Items]
Operating distributions from unconsolidated investments	0
Distributions from unconsolidated investments	0
Ireland [Member]
Schedule of Equity Method Investments [Line Items]
Operating distributions from unconsolidated investments	1.2
Distributions from unconsolidated investments	0
Ireland [Member] | Multifamily [Member]
Schedule of Equity Method Investments [Line Items]
Operating distributions from unconsolidated investments	0
Distributions from unconsolidated investments	0
Ireland [Member] | Commercial [Member]
Schedule of Equity Method Investments [Line Items]
Operating distributions from unconsolidated investments	1.2
Distributions from unconsolidated investments	0
Ireland [Member] | Residential [Member]
Schedule of Equity Method Investments [Line Items]
Operating distributions from unconsolidated investments	0
Distributions from unconsolidated investments	0
Other [Member]
Schedule of Equity Method Investments [Line Items]
Operating distributions from unconsolidated investments	0
Distributions from unconsolidated investments	1.0
Other [Member] | Multifamily [Member]
Schedule of Equity Method Investments [Line Items]
Operating distributions from unconsolidated investments	0
Distributions from unconsolidated investments	0
Other [Member] | Commercial [Member]
Schedule of Equity Method Investments [Line Items]
Operating distributions from unconsolidated investments	0
Distributions from unconsolidated investments	0
Other [Member] | Residential [Member]
Schedule of Equity Method Investments [Line Items]
Operating distributions from unconsolidated investments	0
Distributions from unconsolidated investments	$ 1.0