Discontinued Operations (Details) (USD $)	3 Months Ended								12 Months Ended																						9 Months Ended	12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Wholly Owned Properties [Member]	Dec. 31, 2012 Wholly Owned Properties [Member]	Dec. 31, 2011 Wholly Owned Properties [Member]	Dec. 31, 2013 Discontinued operations	Dec. 31, 2012 Discontinued operations	Dec. 31, 2011 Discontinued operations	Dec. 31, 2013 Parent Company [Member]	Dec. 31, 2012 Parent Company [Member]	Dec. 31, 2011 Parent Company [Member]	Dec. 31, 2013 Operating Segments [Member] property	Dec. 31, 2012 Operating Segments [Member] property	Dec. 31, 2011 Operating Segments [Member] property	Dec. 31, 2012 Operating Segments [Member] Discontinued operations property	Dec. 31, 2011 Operating Segments [Member] Discontinued operations property	Dec. 31, 2012 Operating Segments [Member] Continuing operations property	Dec. 31, 2011 Operating Segments [Member] Continuing operations property	Dec. 31, 2013 Land [Member] property	Dec. 31, 2012 Land [Member] property	Dec. 31, 2011 Land [Member] property	Sep. 30, 2013 BRE Throne Holdings LLC (BRET) [Member]	Dec. 31, 2012 BRE Throne Holdings LLC (BRET) [Member]	Dec. 31, 2013 BRE Throne Holdings LLC (BRET) [Member]	Jul. 25, 2012 BRE Throne Holdings LLC (BRET) [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Investments in real estate partnerships (note 4)	$ 358,849,000				$ 442,927,000				$ 358,849,000	$ 442,927,000								$ 358,849,000	$ 442,927,000													$ 48,757,000	$ 0	$ 47,500,000
Proceeds from sale of real estate investments									212,632,000	352,707,000	86,233,000							212,632,000	352,707,000	86,233,000
Proceeds from Sale of Real Estate																																321,000,000
Provision for impairment									6,000,000	74,816,000	15,883,000				0	54,500,000	3,416,000	6,000,000	20,316,000	12,466,000												18,100,000
Gain Loss On Sale Of Properties Including Discontinued Operations									59,656,000	24,013,000	8,346,000							59,656,000	24,013,000	8,346,000
Gain (Loss) on Sale of Properties																		1,703,000	2,158,000	2,404,000
Number of Real Estate Properties Sold																					12	20	8	5	7	15	1	10	7	8
Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest												100.00%	100.00%	100.00%
Revenues included in Discontinued Operations	126,005,000	120,317,000	122,307,000	120,378,000	116,230,000	113,760,000	123,413,000	120,526,000							14,924,000	26,413,000	37,679,000	489,007,000	473,929,000	470,449,000
Operating Expenses															7,592,000	15,514,000	23,520,000	324,687,000	307,493,000	303,976,000
Other Operating Income (Expense), Net															0	0	0
Discontinued Operation, Tax Effect of Discontinued Operation									0	600,000	(289,000)				0	(18,000)	106,000
Operating income (loss)																		$ 7,332,000	$ (43,583,000)	$ 10,637,000
Preferred Stock, Dividend Rate, Percentage																															10.50%