Interest Income And Interest Expense (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Interest Income And Interest Expense [Abstract]
Investment securities	$ 62,155	$ 45,946	$ 37,217
Bank loans, net of unearned income	38,608	28,595	19,495
Margin balances	18,222	19,079	18,681
Other	23,544	15,085	13,806
Total interest income	142,529	108,705	89,199
Senior notes	20,648	11,777
Bank deposits	11,775	15,013	16,731
Other	13,945	6,580	8,573
Total interest expense	$ 46,368	$ 33,370	$ 25,304