Condensed Consolidated Statements of Financial Condition (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Assets
Cash and cash equivalents	$ 239,115	$ 261,897
Cash restricted or segregated under regulations and other	72,761	71,202
Deposits with clearing organizations	43,476	74,771
Securities owned, at fair value	14,173	7,436
Receivables from brokers, dealers and clearing organizations	1,740,800	1,018,342
Receivables from customers	1,336,535	591,004
Premises and equipment, net	62,306	66,171
Capitalized software, net	38,015	37,892
Intangibles, net	28,832	31,201
Income taxes receivable	81	54
Deferred taxes	29,278	34,130
Other assets	24,619	15,787
Total assets	3,629,991	2,209,887
Liabilities:
Accounts payable and accrued expenses	175,882	175,931
Short-term bank loans	141,654	73,539
Payables to brokers, dealers and clearing organizations	1,709,697	1,025,268
Payables to customers	1,134,612	469,264
Securities sold, not yet purchased, at fair value	9,108	2,953
Income taxes payable	13,990	14,805
Deferred taxes	9	363
Term debt	24,081	30,332
Total liabilities	3,209,033	1,792,455
Commitments and contingencies
Stockholders' Equity:
Preferred stock, $0.01 par value; 1,000,000 shares authorized; no shares issued or outstanding
Common stock, $0.01 par value; 100,000,000 shares authorized; 52,191,351 and 52,158,374 shares issued at June 30, 2014 and December 31, 2013, respectively	522	522
Additional paid-in capital	233,768	240,057
Retained earnings	463,116	436,570
Common stock held in treasury, at cost; 16,944,029 and 16,005,500 shares at June 30, 2014 and December 31, 2013, respectively	(287,166)	(268,253)
Accumulated other comprehensive income (net of tax)	10,718	8,536
Total stockholders' equity	420,958	417,432
Total liabilities and stockholders' equity	$ 3,629,991	$ 2,209,887