Notes Payable and Subordinated Borrowings - Schedule of Future Payments (Details) - Senior Notes And Subordinated Debt [Member] $ in Thousands	Dec. 31, 2017 USD ($)
Debt Instrument [Line Items]
2018	$ 9,311
2019	16,050
2020	8,937
2021	46,010
2022	7,083
Thereafter	148,176
Total	$ 235,567