Agreements and Transactions with Related Parties (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Amounts Included in the Consolidated Statements of Income:
Asset management fees	$ 6,846	$ 5,365	$ 13,465	$ 10,476
Available Cash Distribution	4,590	4,847	9,269	9,124
Personnel and overhead reimbursements	2,503	1,628	5,622	4,267
Office rent reimbursements	321	365	702	583
Acquisition expenses	298	404	1,191	1,170
Interest expense on deferred acquisition fees and loan from affiliate	129	206	280	442
Operating expenses	14,687	12,815	30,529	26,062
Acquisition Fees Capitalized:
Current acquisition fees	1,351	862	1,355	2,187
Deferred acquisition fees	682	364	690	1,218
Transaction fees incurred	2,033	1,226	2,045	3,405
Due to Affiliates:
Deferred acquisition fees, including interest	9,446		9,446		15,573
Asset management fees payable	2,284		2,284		1,972
Accounts payable	1,843		1,843		2,200
Reimbursable costs	425		425		264
Subordinated disposition fees	202		202		202
Due to affiliates	$ 14,200		$ 14,200		$ 20,211