| Component: (Network and Table) | |
|---|---|
| Network | 00500 - Statement - Consolidated Statements of Cash Flows (http://www.itg.com/role/StatementConsolidatedStatementsOfCashFlows)  | 
| Table | (Implied) | 
| Reporting Entity [Axis] | 0000920424 (http://www.sec.gov/CIK) | 
| Condensed Consolidated Statements of Cash Flows | Period [Axis] | ||
|---|---|---|---|
2016-01-01 - 2016-12-31  | 2015-01-01 - 2015-12-31  | 2014-01-01 - 2014-12-31  | |
Condensed Consolidated Statements of Cash Flows  | |||
Cash flows from Operating Activities:  | |||
Net (loss) income  | (25,918,000)   | 91,570,000    | 50,892,000    | 
Adjustments to reconcile net (loss) income to net cash provided by operating activities:  | |||
Depreciation and amortization  | |||
Deferred income tax (benefit) expense  | (  | (  | |
Provision for doubtful accounts  | (  | ||
Non-cash share based compensation  | |||
Gain on sale of investment research operations  | (  | (  | |
Changes in operating assets and liabilities:  | |||
Cash restricted or segregated under regulations and other  | (  | (  | |
Deposits with clearing organizations  | (  | ||
Securities owned, at fair value  | (  | ||
Receivables from brokers, dealers and clearing organizations  | (  | ||
Receivables from customers  | (  | (  | |
Accounts payable and accrued expenses  | (  | ||
Payables to brokers, dealers and clearing organizations  | (  | (  | |
Payables to customers  | (  | (  | |
Securities sold, not yet purchased, at fair value  | (  | (  | |
Income taxes receivable/payable  | (  | ||
Excess tax benefit from share-based payment arrangements  | (  | (  | (  | 
Other, net  | (  | (  | (  | 
Net cash provided by operating activities  | |||
Cash flows from Investing Activities:  | |||
Proceeds from sale of investment research operations, net of deal costs  | |||
Investment in unconsolidated affiliates  | (  | ||
Acquisition of subsidiaries, net of acquired cash  | (  | ||
Capital purchases  | (  | (  | (  | 
Capitalization of software development costs  | (  | (  | (  | 
Net cash used in investing activities  | (  | (  | |
Cash flows from Financing Activities:  | |||
Repayments of long term debt  | (  | (  | (  | 
(Repayments of) proceeds from borrowing under short-term bank loans  | (  | ||
Debt issuance costs  | (  | (  | |
Excess tax benefit from share-based payment arrangements  | |||
Common stock issued  | |||
Common stock repurchased  | (  | (  | (  | 
Dividends paid  | (  | (  | |
Shares withheld for net settlements of share-based awards  | (  | (  | (  | 
Net cash used in financing activities  | (  | (  | (  | 
Effect of exchange rate changes on cash and cash equivalents  | (  | (  | |
Net increase (decrease) in cash and cash equivalents  | (  | ||
Cash and cash equivalents - beginning of year  | 330,653,000    | ||
Cash and cash equivalents - end of period  | 277,977,000    | 330,653,000    | 275,210,000    | 
Supplemental cash flow information:  | |||
Interest paid  | |||
Income taxes paid  | |||
Supplemental disclosure of non-cash investing and financing activities:  | |||
Capital expenditures funded by financing from seller  | |||