Net Income (Loss) Available to Common Stockholders Per Share of the Company (Details) (USD $) In Thousands, except Share data	3 Months Ended				9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010		Sep. 30, 2011		Sep. 30, 2010
Numerator:
Income from continuing operations	$ 1,427		$ 3,319		$ 9,021		$ 13,491
Loss (income) from continuing operations attributable to noncontrolling common units of the Operating Partnership	67		15		65		(94)
Preferred distributions and dividends	(3,799)		(3,799)		(11,397)		(11,397)
Allocation to participating securities (nonvested shares and RSUs)	(330)		(273)		(979)		(877)
Numerator for basic and diluted (loss) income from continuing operations available to common stockholders	(2,635)		(738)		(3,290)		1,123
Income from discontinued operations	12,863	[1]	350	[1]	13,608	[1]	1,011	[1]
Income from discontinued operations attributable to noncontrolling common units of the Operating Partnership	(363)		(11)		(385)		(34)
Numerator for basic and diluted net income (loss) available to common stockholders	$ 9,865		$ (399)		$ 9,933		$ 2,100
Denominator:
Weighted average common shares outstanding-basic (Note 15)	58,355,127		52,274,316		56,136,477		48,561,614
Effect of dilutive securities - Exchangeable Notes and stock options	0		0		0		3,414
Weighted average common shares outstanding-diluted	58,355,127		52,274,316		56,136,477		48,565,028
Basic earnings per share:
(Loss) income from continuing operations available to common stockholders per common share-basic	$ (0.05)		$ (0.01)		$ (0.06)		$ 0.02
Income from discontinued operations per common share	$ 0.22		$ 0.00		$ 0.24		$ 0.02
Net (loss) income available to common stockholders per share-basic (Note 15)	$ 0.17		$ (0.01)		$ 0.18		$ 0.04
Diluted earnings per share:
(Loss) income from continuing operations available to common stockholders per common share-diluted	$ (0.05)		$ (0.01)		$ (0.06)		$ 0.02
Income from discontinued operations per common share	$ 0.22		$ 0.00		$ 0.24		$ 0.02
Net (loss) income available to common stockholders per share-diluted (Note 15)	$ 0.17		$ (0.01)		$ 0.18		$ 0.04

[1] Income from discontinued operations is from our Reportable Segment - Office Properties.