Discontinued Operations (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended											12 Months Ended	0 Months Ended	12 Months Ended		12 Months Ended				0 Months Ended			12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2011 Other real estate [Member]	Dec. 31, 2010 Other real estate [Member]	Dec. 31, 2009 Other real estate [Member]	Dec. 31, 2011 Washington DC1140 Connecticut Avenue [Member]	Jan. 12, 2011 Washington DC1140 Connecticut Avenue [Member]	Dec. 31, 2010 Washington DC1140 Connecticut Avenue [Member]	Dec. 31, 2011 Washington DC1227 Twenty Fifth Street [Member]	Dec. 31, 2010 Washington DC1227 Twenty Fifth Street [Member]	Dec. 31, 2011 Washington DC1140 Connecticut Avenue and 1227 Twenty Fifth Street [Member]	Sep. 01, 2009 Washington DC1999K Street [Member] sqft	Dec. 31, 2011 High Point Complex [Member]	Dec. 31, 2010 High Point Complex [Member]	Dec. 31, 2010 Petangon Row [Member]	Dec. 31, 2009 Retail Properties [Member] Properties	Dec. 31, 2011 Retail Properties [Member]	Dec. 31, 2010 Retail Properties [Member]	Jan. 06, 2012 350 West Mart Center [Member] sqft	Dec. 31, 2011 350 West Mart Center [Member]	Dec. 31, 2010 350 West Mart Center [Member]	Dec. 31, 2011 Three retail properties [Member]
Disposal Group Including Discontinued Operation Additional Disclosures Abstract
Number of additional retail properties sold																	15
Sale of real estate property, gross								$ 127,000
Cash Sale of Real Estate													207,800			14,992	55,000			228,000			40,990
Gain (Loss) from Disposal of real estate				5,761	2,506	45,284						45,862	41,211				4,073			54,200
Square Footage Of Real Estate Property													250,000							1,200,000
Disposal Group Not Discontinued Operation Income Statement Disclosures Abstract
Total revenues	45,745	82,917	96,853
Total expenses	29,943	77,511	78,148
Operating Income from Discontinued Operations	15,802	5,406	18,705
Net gain on extinguishment of debt														83,907
Net gains on sale of real estate				5,761	2,506	45,284						45,862	41,211				4,073			54,200
Disposal Group Including Discontinued Operation Litigation Loss Accruals Impairments	(5,799)	(15,056)	(14,060)
Income (loss) from discontinued operations	145,533	(7,144)	49,929
Disposal Group Including Discontinued Operation Unclassified Balance Sheet Disclosures Abstract
Assets related to discontinued operations	251,202	519,285					0		36,271	0	43,630			0	154,563			77,422	121,837		173,780	162,984
Liabilities related to discontinued operations	$ 14,153	$ 267,652					$ 0		$ 18,948					$ 0	$ 236,974			$ 7,792	$ 11,730		$ 6,361	$ 0