Rental Property Revenues (Tables)

12 Months Ended

Dec. 31, 2011

Rental Property Revenues [Abstract]

Future minimum rentals to be received under existing non-cancelable leases

		September 30,		September 30,		September 30,
	Office		Retail		Total
2012	$	82,153	$	23,338	$	105,491
2013		81,797		24,228		106,025
2014		79,737		23,350		103,087
2015		73,031		22,789		95,820
2016		65,992		18,942		84,934
Thereafter		268,816		51,106		319,922
	$	651,526	$	163,753	$	815,279