Risk Management and Use of Derivative Financial Instruments (Narratives) (Details) (USD $)	3 Months Ended		6 Months Ended				6 Months Ended					3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013	Jun. 30, 2014 Interest rate swap	Jun. 30, 2014 Interest rate swap Interest expense	Jun. 30, 2014 Interest rate swap Other income and expense	Jun. 30, 2014 Interest rate swap Noncontrolling interest Interest expense	Nov. 30, 2012 Embedded derivatives	Jun. 30, 2014 Interest rate cap	Jun. 30, 2014 Interest rate cap Noncontrolling interest	Jun. 30, 2013 Interest rate cap Noncontrolling interest	Jun. 30, 2014 Interest rate cap Noncontrolling interest	Jun. 30, 2013 Interest rate cap Noncontrolling interest
Derivatives, Fair Value [Line Items]
Foreign currency exchange rate										1.278
Derivatives, gain (loss) recognized in OCI, effective portion, net	$ (1,573,000)	$ 3,094,000	$ (4,024,000)	$ 13,412,000								$ 200,000	$ 100,000	$ 300,000	$ 300,000
Footnote Details
Debt, interest rate at period end												2.70%		2.70%
Cap rate												4.00%		4.00%
Derivative notional amount						209,154,000					113,842,000	51,200,000		51,200,000
Derivative fair value	(13,963,000)		(13,963,000)			(5,163,000)					0	0		0
Derivative Instrument Detail
Estimated amount reclassified from OCI to income, derivatives							7,500,000	1,300,000	100,000
Collateral received	0		0
Total credit exposure on derivatives	1,800,000		1,800,000
Total credit exposure on derivatives to a single counterparty	1,300,000		1,300,000
Derivatives, net liability position	27,900,000		27,900,000		25,100,000
Aggregate termination value for immediate settlement	$ 29,700,000		$ 29,700,000		$ 27,100,000