Receivables From And Payables To Brokers, Dealers And Clearing Organizations (Amounts Payable To Brokers, Dealers, And Clearing Organizations) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Due To And From Broker Dealers And Clearing Organizations [Abstract]
Deposits received for securities loaned	$ 104,138	$ 4,215
Payable to clearing organizations	40,738	2,443
Securities failed to receive	26,080	7,365
Payables to broker, dealers and clearing organizations, Total	$ 170,956	$ 14,023