Loans Held for Investment and Allowance for Loan Losses (Loans) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total unpaid principal balance	$ 651,970	$ 543,790
Net deferred origination costs	11,419	8,952
Total loans held for investment	663,389	552,742
Term loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total unpaid principal balance	573,076	482,596
Lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total unpaid principal balance	$ 78,894	$ 61,194