Receivables From And Payables To Brokers, Dealers, And Clearing Agencies (Schedule Of Due To (From) Broker-Dealers And Clearing Organizations) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Receivables from Brokers-Dealers and Clearing Organizations [Abstract]
Deposits with clearing organizations	$ 1,428	$ 1,516
Unsettled regular way trades, net		9,653
Receivable from clearing organizations	418	1,084
Receivables from brokers, dealers, and clearing agencies	1,846	12,253
Payables to Broker-Dealers and Clearing Organizations [Abstract]
Unsettled regular way trades, net	5,600
Margin payable	25,111	96,211
Payables to brokers, dealers, and clearing agencies	$ 30,711	$ 96,211