Related Party Transactions (Details Textual) (USD $)	3 Months Ended		9 Months Ended			9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Jan. 15, 2008 Del Monte Center [Member]	Sep. 30, 2012 ICW Plaza [Member]	Sep. 30, 2011 ICW Plaza [Member]	Sep. 30, 2011 Valencia Corporate Center [Member]	Sep. 30, 2012 Reimbursements [Member]	Sep. 30, 2011 Reimbursements [Member]
Related Party Transactions (Textual) [Abstract]
Unsecured loans					$ 12,000,000
Debt instrument, maturity date			Mar. 01, 2013
Percentage interest on notes payable to affiliates					10.00%
Total rental income	59,915,000	53,278,000	169,199,000	146,860,000		1,600,000	1,700,000	1,200,000
Investment in WBW CHP LLC, in percentage			47.70%
Recovered reimbursements of operating expenses of WBW CHP LLC									$ 800,000	$ 700,000