Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Cash flows from Operating Activities:
Net income	$ 37,911	$ 21,423
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	37,889	40,281
Deferred income tax expense	1,571	1,121
Provision for doubtful accounts	424	(671)
Share-based compensation	12,533	15,056
Non-cash restructuring charges		357
Fixed asset disposal		649
Changes in operating assets and liabilities:
Cash restricted or segregated under regulations and other	(625)	(9,399)
Deposits with clearing organizations	41,136	(3,327)
Securities owned, at fair value	(15,276)	(2,019)
Receivables from brokers, dealers and clearing organizations	(1,107,090)	(539,304)
Receivables from customers	(809,418)	(398,998)
Accounts payable and accrued expenses	9,755	9,214
Payables to brokers, dealers and clearing organizations	654,356	187,119
Payables to customers	1,175,003	712,819
Securities sold, not yet purchased, at fair value	20,776	2,149
Income taxes receivable/payable	(69)	14,240
Excess tax benefit	(1,065)	(219)
Other, net	(5,153)	(3,188)
Net cash provided by operating activities	52,658	47,303
Cash flows from Investing Activities:
Investment in unconsolidated affiliates	(2,669)	(474)
Acquisition of subsidiaries, net of acquired cash	(18,293)
Capital purchases	(8,239)	(29,757)
Capitalization of software development costs	(19,905)	(17,152)
Net cash used in investing activities	(49,106)	(47,383)
Cash flows from Financing Activities:
Proceeds of short-term bank loans, net	16,387	30,332
Repayments of term loans	(9,395)	(6,515)
Proceeds from sales-lease back transactions		20,562
Excess tax benefit	1,065	219
Common stock issued	990	162
Common stock repurchased	(36,128)	(24,001)
Shares withheld for net settlements of share-based awards	(6,586)	(3,715)
Net cash provided by (used in) financing activities	(33,667)	17,044
Effect of exchange rate changes on cash and cash equivalents	(3,321)	(1,272)
Net (decrease) increase in cash and cash equivalents	(33,436)	15,692
Cash and cash equivalents - beginning of year	261,897	245,875
Cash and cash equivalents - end of period	228,461	261,567
Supplemental cash flow information
Interest paid	2,982	2,270
Income taxes (refunded) paid	$ 7,579	$ (4,546)