Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Cash flows from Operating Activities:
Net income (loss)	$ 13,708	$ (241,638)
Adjustments to reconcile net income (loss) to net cash used in operating activities
Depreciation and amortization	26,898	28,493
Deferred income tax expense	579	(21,725)
Provision for doubtful accounts	(435)	851
Share-based compensation	10,132	5,994
Non-cash restructuring charges	357
Fixed asset disposal	649
Goodwill impairment		274,285
Changes in operating assets and liabilities:
Cash restricted or segregated under regulations and other	(4,331)	6,067
Deposits with clearing organizations	4,930	(44)
Securities owned, at fair value	2,909	(487)
Receivables from brokers, dealers and clearing organizations	(82,533)	(71,548)
Receivables from customers	(624,406)	(114,187)
Accounts payable and accrued expenses	8,270	(37,394)
Payables to brokers, dealers and clearing organizations	253,467	(77,284)
Payables to customers	432,803	230,573
Securities sold, not yet purchased, at fair value	(2,539)	1,321
Income taxes receivable/payable	14,539	(2,885)
Excess tax benefit	(207)
Other, net	(5,922)	(2,424)
Net cash provided by (used in) operating activities	48,868	(22,032)
Cash flows from Investing Activities:
Investment in unconsolidated affiliates	(474)
Capital purchases	(20,574)	(11,835)
Capitalization of software development costs	(11,836)	(13,008)
Net cash used in investing activities	(32,884)	(24,843)
Cash flows from Financing Activities:
Repayments of long term debt	(3,712)	(3,477)
Proceeds from borrowing under short-term bank loans	7,957	6,809
Proceeds from sales-leaseback transaction	18,157	1,901
Common stock issued	497	2,116
Common stock repurchased	(17,938)	(13,183)
Shares withheld for net settlements of share-based awards	(3,617)	(2,250)
Excess tax benefit	207
Net cash provided by (used in) financing activities	1,551	(8,084)
Effect of exchange rate changes on cash and cash equivalents	(4,376)	(401)
Net increase (decrease) in cash and cash equivalents	13,159	(55,360)
Cash and cash equivalents - beginning of year	245,875	284,188
Cash and cash equivalents - end of period	259,034	228,828
Supplemental cash flow information
Interest paid	1,522	1,392
Income taxes (refunded) paid	$ (7,149)	$ 4,155