Segment Information (Tables)

12 Months Ended

Dec. 31, 2011

Segment Reporting Information, Revenue for Reportable Segment [Abstract]

Real Estate Rental Revenue, Percent

Real estate rental revenue as a percentage of the total for each of the four reportable operating segments is as follows:

	Year Ended December 31,
	2011		2010		2009
Office	49	%	48	%	48	%
Medical office	16	%	17	%	18	%
Retail	17	%	16	%	16	%
Multifamily	18	%	19	%	18	%

Percentage of Real Estate Assets by Segment

The percentage of total income producing real estate assets, at cost, for each of the four reportable operating segments is as follows:

	December 31,
	2011		2010
Office	53	%	48	%
Medical office	17	%	19	%
Retail	17	%	17	%
Multifamily	13	%	16	%

Reconciliation Of Net Operating Income Of Reportable Segments

	2011
	Office		Medical Office		Retail		Multifamily		Industrial/Flex		Corporate and Other		Consolidated
Real estate rental revenue	$	142,870	$	45,257	$	50,421	$	50,979			$	—	$	289,527
Real estate expenses	48,960		14,242		14,273		19,717				—		97,192
Net operating income	$	93,910	$	31,015	$	36,148	$	31,262			$	—	$	192,335
Depreciation and amortization													(93,297		)
Interest expense													(66,473		)
General and administrative													(15,728		)
Acquisition costs													(3,607		)
Other income (expense)													1,144
Real estate impairment													(14,526		)
Loss on extinguishment of debt, net													(976		)
Gain from non-disposal activities													—
Discontinued operations:
Income from discontinued operations													10,153
Gain on sale of real estate													97,491
Income tax benefit (expense)													(1,138		)
Net income													105,378
Less: Net income attributable to noncontrolling interests													(494		)
Net income attributable to the controlling interests													$	104,884
Capital expenditures	$	21,065	$	5,654	$	2,922	$	2,823	$	351	$	621	$	33,436
Total assets	$	1,118,074	$	347,735	$	365,164	$	247,170	$	—	$	42,615	$	2,120,758

	2010
	Office		Medical Office		Retail		Multifamily		Industrial/Flex		Corporate and Other		Consolidated
Real estate rental revenue	$	123,860	$	45,028	$	41,003	$	48,599	$	—	$	—	$	258,490
Real estate expenses	42,392		14,715		10,310		19,243		—		—		86,660
Net operating income	$	81,468	$	30,313	$	30,693	$	29,356	$	—	$	—	$	171,830
Depreciation and amortization													(80,066		)
Interest expense													(67,229		)
General and administrative													(14,406		)
Acquisition costs													(1,161		)
Other income (expense)													1,193
Loss on extinguishment of debt, net													(9,176		)
Gain from non-disposal activities													7
Discontinued operations:
Income from discontinued operations													14,968
Gain on sale of real estate													21,599
Net income													37,559
Less: Net income attributable to noncontrolling interests													(133		)
Net income attributable to the controlling interests													$	37,426
Capital expenditures	$	13,983	$	4,986	$	1,982	$	2,387	$	1,707	$	392	$	25,437
Total assets	$	938,638	$	353,508	$	313,003	$	228,769	$	225,206	$	108,757	$	2,167,881

	2009
	Office		Medical Office		Retail		Multifamily		Industrial/Flex		Corporate and Other		Consolidated
Real estate rental revenue	$	123,347	$	44,911	$	41,821	$	46,470	$	—	$	—	$	256,549
Real estate expenses	43,897		15,218		10,680		19,494		—		—		89,289
Net operating income	$	79,450	$	29,693	$	31,141	$	26,976	$	—	$	—	$	167,260
Depreciation and amortization													(77,549		)
Interest expense													(72,694		)
General and administrative													(13,118		)
Acquisition costs													(788		)
Other income (expense)													1,205
Gain on extinguishment of debt, net													5,336
Gain from non-disposal activities													71
Discontinued operations:
Income from discontinued operations													17,877
Gain on sale of real estate													13,348
Net income													40,948
Less: Net income attributable to noncontrolling interests													(203		)
Net income attributable to the controlling interests													$	40,745
Capital expenditures	$	14,200	$	6,613	$	1,270	$	2,287	$	2,967	$	351	$	27,688
Total assets	$	926,433	$	360,220	$	225,548	$	240,442	$	251,986	$	40,596	$	2,045,225