Transactions with Affiliates (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Chairman and Chief Executive Officer, and Certain Family Partnerships and Affiliates [Member]
Related Party Transaction [Line Items]
Investment commitments with related party	$ 2,400,000	$ 6,300,000
Due to related parties, current	49,000		42,000
Overhead recovery from related parties	38,000	36,000
Expense reimbursements from related parties	38,000	36,000
Other Affiliated Entities [Member]
Related Party Transaction [Line Items]
Overhead recovery from related parties	26,000	24,000
Expense reimbursements to related parties	12,000	9,000
Expense reimbursements from related parties	26,000	24,000
Estimated annual rental expense	480,000
Lease term	7 years
Rent expense paid	$ 120,000	$ 81,000