Condensed Consolidated Statements of Financial Condition (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Assets
Cash and cash equivalents	$ 223,032	$ 284,188
Cash restricted or segregated under regulations and other	67,158	71,496
Deposits with clearing organizations	30,137	25,538
Securities owned, at fair value	6,385	5,277
Receivables from brokers, dealers and clearing organizations	1,575,268	871,315
Receivables from customers	1,465,403	472,509
Premises and equipment, net	42,661	43,023
Capitalized software, net	49,793	51,258
Goodwill	274,283	274,292
Other intangibles, net	38,467	39,594
Income taxes receivable	6,322	6,838
Deferred taxes	7,095	16,493
Other assets	22,191	16,248
Total assets	3,808,195	2,178,069
Liabilities:
Accounts payable and accrued expenses	143,086	181,224
Short-term bank loans	86,536	1,606
Payables to brokers, dealers and clearing organizations	1,893,413	1,079,773
Payables to customers	989,646	207,738
Securities sold, not yet purchased, at fair value	1,507	438
Income taxes payable	5,029	11,460
Deferred taxes	715	719
Term debt	22,259	23,997
Total liabilities	3,142,191	1,506,955
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; 51,961,710 and 51,899,229 shares issued at March 31, 2012 and December 31, 2011, respectively	520	519
Additional paid-in capital	237,357	249,469
Retained earnings	658,802	653,344
Common stock held in treasury, at cost; 13,159,963 and 12,679,948 shares at March 31, 2012 and December 31, 2011, respectively	(241,717)	(240,559)
Accumulated other comprehensive income (net of tax)	11,042	8,341
Total stockholders' equity	666,004	671,114
Total liabilities and stockholders' equity	$ 3,808,195	$ 2,178,069