Other Assets (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Summary of other assets
Prepaid rent	$ 3,194	$ 3,589
Debt issuance costs, net of amortization	7,701	4,486
Deposits and insurance binders	4,115	3,640
Other	6,062	6,155
Total other assets	$ 21,072	$ 17,870