Reportable Segments (Net Income (Loss) Reconciliation) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Reconciliation from Segment Totals to Consolidated
Interest expense	$ (1,985)	$ (197)	$ (1,045)
Reimbursed Expenses	(7,063)	(6,207)	(6,297)
Other expenses	(488)	(100,131)	(2,554)
Gain on sale of third party management and leasing business	(7,459)	0	0
Dividends, Preferred Stock	(12,907)	(12,907)	(12,907)
Impairment loss on depreciable investment property, net of amounts attributable to noncontrolling interests	(14,278)	(107,763)	(2,554)
NET INCOME (LOSS) AVAILABLE TO COMMON STOCKHOLDERS	32,821	(141,332)	(27,480)
Total Assets	1,124,242	1,235,535
Office
Reconciliation from Segment Totals to Consolidated
Net operating income	80,907	75,387	72,792
Fee income	0	0	0
Sales less costs of sales	0	0	0
Other income	3,037	1,475	416
Third party management and leasing expenses	0	0	0
Interest expense	0	0	0
Separation expenses	0	0	0
Reimbursed Expenses	0	0	0
General and administrative expenses	0	0	0
Other expenses	0	0	0
Impairment loss	0	0	0
Gain on sale of third party management and leasing business	0
Dividends, Preferred Stock	0	0	0
Funds from operations available to common stockholders	83,944	76,862	73,208
Total Assets	736,867	732,857	671,540
Retail
Reconciliation from Segment Totals to Consolidated
Net operating income	29,429	31,583	31,729
Fee income	0	0	0
Sales less costs of sales	0	0	0
Other income	603	151	146
Third party management and leasing expenses	0	0	0
Interest expense	0	0	0
Separation expenses	0	0	0
Reimbursed Expenses	0	0	0
General and administrative expenses	0	0	0
Other expenses	0	0	0
Impairment loss	0	0	0
Gain on sale of third party management and leasing business	0
Dividends, Preferred Stock	0	0	0
Funds from operations available to common stockholders	30,032	31,734	31,875
Total Assets	151,417	375,923	348,470
Land
Reconciliation from Segment Totals to Consolidated
Net operating income	0	0	0
Fee income	4,915	5,236	12,502
Sales less costs of sales	0	0	0
Other income	0	0	0
Third party management and leasing expenses	0	0	0
Interest expense	0	0	0
Separation expenses	0	0	0
Reimbursed Expenses	0	0	0
General and administrative expenses	0	0	0
Other expenses	0	(125,526)	(5,714)
Impairment loss	0	0	0
Gain on sale of third party management and leasing business	0
Dividends, Preferred Stock	0	0	0
Funds from operations available to common stockholders	4,915	(120,290)	6,788
Total Assets	50,520	108,172	261,323
Third Party Management and Leasing
Reconciliation from Segment Totals to Consolidated
Net operating income	0	0	0
Fee income	0	0	0
Sales less costs of sales	16,365	19,359	18,977
Other income	0	0	0
Third party management and leasing expenses	(13,675)	(16,585)	(17,393)
Interest expense	0	0	0
Separation expenses	0	0	0
Reimbursed Expenses	0	0	0
General and administrative expenses	0	0	0
Other expenses	0	0	0
Impairment loss	0	0	0
Gain on sale of third party management and leasing business	7,459
Dividends, Preferred Stock	0	0	0
Funds from operations available to common stockholders	10,149	2,774	1,584
Total Assets	0	4,302	4,050
Other
Reconciliation from Segment Totals to Consolidated
Net operating income	121	3,583	3,721
Fee income	309	2,250	7,898
Sales less costs of sales	17,797	13,821	14,443
Other income	1,513	578	750
Third party management and leasing expenses	0	0	0
Interest expense	(1,984)	(197)	(1,045)
Separation expenses	(23,208)	(24,166)	(28,517)
Reimbursed Expenses	(7,063)	(6,208)	(6,297)
General and administrative expenses	(28,154)	(32,515)	(41,432)
Other expenses	(488)	(3,608)	(586)
Impairment loss	(8,484)	(8,586)	(16,702)
Gain on sale of third party management and leasing business	0
Dividends, Preferred Stock	(12,907)	(12,907)	(12,907)
Funds from operations available to common stockholders	(62,548)	(67,955)	(80,674)
Total Assets	185,438	14,281	85,899
Total
Reconciliation from Segment Totals to Consolidated
Net operating income	110,457	110,553	108,242
Fee income	5,224	7,486	20,400
Sales less costs of sales	34,162	33,180	33,420
Other income	5,153	2,204	1,312
Third party management and leasing expenses	(13,675)	(16,585)	(17,393)
Interest expense	(1,984)	(197)	(1,045)
Separation expenses	(23,208)	(24,166)	(28,517)
Reimbursed Expenses	(7,063)	(6,208)	(6,297)
General and administrative expenses	(28,154)	(32,515)	(41,432)
Other expenses	(488)	(129,134)	(6,300)
Impairment loss	(8,484)	(8,586)	(16,702)
Gain on sale of third party management and leasing business	7,459
Dividends, Preferred Stock	(12,907)	(12,907)	(12,907)
Funds from operations available to common stockholders	66,492	(76,875)	32,781
Real estate depreciation and amortization, including Company's share of joint ventures	(62,043)	(62,709)	(67,728)
Impairment loss on depreciable investment property, net of amounts attributable to noncontrolling interests	(11,748)	(7,632)
Gain on sale of depreciated investment properties including Company's share of joint ventures	40,120	5,884	7,467
NET INCOME (LOSS) AVAILABLE TO COMMON STOCKHOLDERS	32,821	(141,332)	(27,480)
Total Assets	$ 1,124,242	$ 1,235,535	$ 1,371,282