Risk Management and Use of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2011

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of derivative instruments in statement of financial position, fair value

Hedge Product	Hedge Type	Designation		Notional Amount		Strike		Trade Date	Maturity Date	Fair value
Swap	Interest Rate	Cash Flow	(a)	$	200,000	3.623	%	December 6-13, 2011	February 1, 2019	$	2,820
Swap	Interest Rate	Cash Flow	(a)	127,000		2.702	%	December 9-13, 2011	February 1, 2016	340
Swap	Interest Rate	Cash Flow	(a)	50,000		2.470	%	December 13, 2011	February 1, 2015	65
Swap	Interest Rate	Cash Flow	(a)	23,000		2.513	%	December 7-12, 2011	May 1, 2015	27
Swap	Interest Rate	Cash Flow	(a)	27,062		2.750	%	December 21, 2011	September 30, 2017	244
Swap	Interest Rate	Cash Flow	(a)	25,774		3.300	%	December 22, 2011	January 30, 2021	390
				$	452,836					$	3,886