4. Debt ACC5 Term Loan (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012	Mar. 31, 2013 Acc Five Term Loan [Member]	Dec. 02, 2009 Acc Five Term Loan [Member]
Debt Instrument [Line Items]
Mortgage notes payable	$ 115,000		$ 139,600		$ 150,000
Repayments of Notes Payable	138,300	0		138,300
Write off of Deferred Debt Issuance Cost	$ 1,700	$ 0		$ 1,700
Debt Instrument, Maturity Date				Dec. 02, 2014
Debt Instrument, Basis Spread on Variable Rate	1.85%			3.00%