Other Assets (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Other Assets
Deferred leasing costs	$ 14,159	$ 12,444
Deferred rent receivable	17,265	15,017
Deferred financing costs	3,312	2,520
Corporate furniture, fixtures and equipment	7,346	4,152
Internal-use software	8,525	2,300
Other	5,195	6,149
Total	55,802	42,582
Estimated amortization of deferred leasing costs
2014	4,798
2015	3,843
2016	2,132
2017	1,155
2018	760
Thereafter	1,471
Total	$ 14,159	$ 12,444