Borrowings - Broker-Dealer Credit Facilities (Details) $ in Thousands |
3 Months Ended | |||
|---|---|---|---|---|
|
Mar. 31, 2016
USD ($)
item
|
Mar. 31, 2015
USD ($)
|
Dec. 31, 2015
USD ($)
|
Apr. 24, 2015
USD ($)
|
|
| Credit Facilities | ||||
| Interest expense | $ 7,101 | $ 7,602 | ||
| Broker-Dealer Credit Facilities | ||||
| Credit Facilities | ||||
| Number of secured credit facilities | item | 2 | |||
| Broker-Dealer Credit Facility on an uncommitted basis | ||||
| Credit Facilities | ||||
| Maximum borrowing capacity | $ 125,000 | |||
| Interest rate (as a percent) | 1.26% | 1.25% | ||
| Interest expense | $ 300 | $ 100 | ||
| Outstanding principal balance | $ 32,000 | $ 45,000 | ||
| Broker-Dealer Credit Facility on committed basis | ||||
| Credit Facilities | ||||
| Maximum borrowing capacity | $ 75,000 | |||
| Credit facility term | 364 days | |||
| Outstanding principal balance | $ 0 | $ 0 | ||
| Broker-Dealer Credit Facility on committed basis | LIBOR rate | ||||
| Credit Facilities | ||||
| Interest rate margin (as a percent) | 1.25% | |||
| Broker-Dealer Credit Facility on committed basis | Base rate | ||||
| Credit Facilities | ||||
| Interest rate margin (as a percent) | 1.25% | |||