Risk Management and Use of Derivative Financial Instruments (Details 5) In Thousands, unless otherwise specified		12 Months Ended															12 Months Ended
	Dec. 31, 2012 USD ($)	Dec. 31, 2012 Interest rate swap Libor Three Month January [Member] USD ($)	Dec. 31, 2012 Interest rate swap Euribor Three Month July [Member] USD ($)	Dec. 31, 2012 Interest rate swap Euribor Three Month July [Member] EUR (€)	Dec. 31, 2012 Interest rate swap Libor One Month January [Member] USD ($)	Dec. 31, 2012 Interest rate swap Libor One Month December 1 [Member] USD ($)	Dec. 31, 2012 Interest rate swap Euribor Six Month [Member] USD ($)	Dec. 31, 2012 Interest rate swap Euribor Six Month [Member] EUR (€)	Dec. 31, 2012 Interest rate swap Libor One Month October [Member] USD ($)	Dec. 31, 2012 Interest rate swap Libor One Month February [Member] USD ($)	Dec. 31, 2012 Interest rate swap Libor One Month June [Member] USD ($)	Dec. 31, 2012 Interest rate swap Libor One Month December 2 [Member] USD ($)	Dec. 31, 2012 Interest rate swap Libor One Month March [Member] USD ($)	Dec. 31, 2012 Interest rate swap Euribor Three Month June [Member] USD ($)	Dec. 31, 2012 Interest rate swap Euribor Three Month June [Member] EUR (€)	Dec. 31, 2012 Interest rate cap	Dec. 31, 2012 Interest rate cap Libor Three Month August [Member] USD ($)
Derivative Instrument Detail
Notional Amount		$ 25,793		€ 5,845	$ 4,120	$ 1,600		€ 164,250	$ 4,292	$ 92,400	$ 4,459	$ 20,075	$ 9,000		€ 3,852		$ 119,260
Effective Interest Rate		6.60%	5.80%	5.80%	6.00%	4.80%	4.20%	4.20%	4.80%	3.90%	4.60%	4.80%	5.00%	4.30%	4.30%
Effective Date		Jan. 01, 2010	Jul. 01, 2010	Jul. 01, 2010	Jan. 01, 2011	Dec. 01, 2011	Sep. 01, 2011	Sep. 01, 2011	Oct. 01, 2012	Feb. 01, 2012	Jun. 01, 2012	Dec. 01, 2012	Mar. 01, 2012	Jun. 01, 2012	Jun. 01, 2012		Aug. 01, 2009
Expiration Date		Dec. 01, 2019	Nov. 01, 2017	Nov. 01, 2017	Jan. 01, 2021	Dec. 01, 2021	Sep. 01, 2016	Sep. 01, 2016	Nov. 01, 2022	Feb. 01, 2017	Jul. 01, 2022	Dec. 01, 2022	Mar. 01, 2022	May 01, 2017	May 01, 2017		Aug. 01, 2014
Fair Value	$ (20,141)	$ (3,822)	$ (658)		$ (550)	$ (84)	$ (11,200)		$ (99)	$ (2,644)	$ (111)	$ (356)	$ (429)	$ (189)			$ 1
Cap Rate																4.00%
Debt, interest rate at period end																2.86%