Discontinued Operations (Details 2) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Gain (Loss) on Disposition of Rental Properties [Line Items]
Pre-tax gain on disposition of rental properties	$ 0	$ 26,824,000
Quartermaster Plaza [Member]
Gain (Loss) on Disposition of Rental Properties [Line Items]
Pre-tax gain on disposition of rental properties	0	26,373,000
Mesa del Sol - 5600 University SE [Member]
Gain (Loss) on Disposition of Rental Properties [Line Items]
Pre-tax gain on disposition of rental properties	$ 0	$ 451,000