Transactions with Affiliates (Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 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	$ 10,400,000	$ 18,300,000
Due to related parties, current	48,000		42,000
Expense reimbursements from related parties	119,000	113,000
Other Affiliated Entities [Member]
Related Party Transaction [Line Items]
Expense reimbursements from related parties	54,000	52,000
Expense reimbursements to related parties	75,000	73,000
Estimated annual rental expense	480,000
Lease term	7 years
Rent expense paid	$ 360,000	$ 322,000