Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Condensed Consolidated Balance Sheets
Acquired real estate leases, accumulated amortization	$ 45,700	$ 40,062
Tenant rent receivables, allowance for doubtful accounts	110	1,300
Straight-line rent receivable, allowance for doubtful accounts	135	135
Office computers and furniture, accumulated depreciation	626	584
Deferred leasing commissions, accumulated amortization	12,607	11,812
Acquired unfavorable real estate leases, accumulated amortization	$ 5,246	$ 4,870
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	180,000,000	180,000,000
Common stock, shares issued (in shares)	82,937,405	82,937,405
Common stock, shares outstanding (in shares)	82,937,405	82,937,405