Statement of Stockholders' Equity [Abstract]
Dividends declared (usd per share)
Common Stock, Dividends, Per Share, Declared
Earnings Per Share [Abstract]
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table]
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table]
Debt Instrument [Axis]
Debt Instrument [Axis]
Debt Instrument, Name [Domain]
Debt Instrument, Name [Domain]
Convertible Notes Due 2018
Convertible Notes Due 2018 [Member]
Convertible Notes Due 2018 [Member]
Convertible Notes Due 2020
Convertible Notes Due 2020 [Member]
Convertible Notes Due 2020 [Member]
Convertible Notes Due 2022
Convertible Notes Due 2022 [Member]
Convertible Notes Due 2022 [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive stock options excluded from calculation of diluted earnings per share
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount
Common stock threshold for additional dilutive shares (in dollars per share)
Common Stock Threshold for Additional Dilutive Shares, Per Share
Common Stock Threshold for Additional Dilutive Shares, Per Share
Dilutive securities, effect on basic earnings per share, dilutive convertible securities
Dilutive Securities, Effect on Basic Earnings Per Share, Dilutive Convertible Securities
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill [Table]
Schedule of Goodwill [Table]
Consolidation Items [Axis]
Consolidation Items [Axis]
Consolidation Items [Domain]
Consolidation Items [Domain]
Operating Segments
Operating Segments [Member]
Segments [Axis]
Segments [Axis]
Segments [Domain]
Segments [Domain]
Retail
Retail Segment [Member]
Retail Segment [Member]
Institutional
Institutional Segment [Member]
Institutional Segment [Member]
Futures
Futures Segment [Member]
Futures Segment [Member]
Goodwill [Line Items]
Goodwill [Line Items]
Number of reporting units
Number of Reporting Units
Goodwill additions or impairments
Goodwill, Other Increase (Decrease)
Goodwill
Goodwill
Decrease in goodwill
Goodwill, Period Increase (Decrease)
Goodwill [Roll Forward]
Goodwill [Roll Forward]
Goodwill. beginning balance
Foreign currency translation adjustments
Goodwill, Foreign Currency Translation Gain (Loss)
Discontinued operations
Goodwill, Written off Related to Sale of Business Unit
Goodwill. ending balance
Revenue from Contract with Customer [Abstract]
REVENUE RECOGNITION
Revenue from Contract with Customer [Text Block]
Income Tax Disclosure [Abstract]
Provision (benefit) for income taxes
Income Tax Expense (Benefit)
Effective income tax rates (as percent)
Effective Income Tax Rate Reconciliation, Percent
Computation of Earnings Per Share
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]
Brokers and Dealers [Abstract]
Schedule of Receivable from Brokers
Schedule of Due to (from) Broker-Dealers and Clearing Organizations [Table Text Block]
Document Documentand Entity Information [Abstract]
Document Documentand Entity Information [Abstract]
Entity Registrant Name
Entity Registrant Name
Trading Symbol
Trading Symbol
Entity Central Index Key
Entity Central Index Key
Current Fiscal Year End Date
Current Fiscal Year End Date
Entity Filer Category
Entity Filer Category
Entity Emerging Growth Company
Entity Emerging Growth Company
Entity Small Business
Entity Small Business
Document Type
Document Type
Document Period End Date
Document Period End Date
Document Fiscal Year Focus
Document Fiscal Year Focus
Document Fiscal Period Focus
Document Fiscal Period Focus
Amendment Flag
Amendment Flag
Entity Common Stock, Shares Outstanding
Entity Common Stock, Shares Outstanding
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation
Basis of Accounting, Policy [Policy Text Block]
Accounting Pronouncements Recently Adopted and Not Yet Adopted
New Accounting Pronouncements, Policy [Policy Text Block]
Revenue Recognition
Revenue from Contract with Customer [Policy Text Block]
Income Statement [Abstract]
Gain on sale
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax
Income tax
Discontinued Operation, Tax Effect of Discontinued Operation
Disaggregation of Revenue [Table]
Disaggregation of Revenue [Table]
Contract with Customer, Sales Channel [Axis]
Contract with Customer, Sales Channel [Axis]
Contract with Customer, Sales Channel [Domain]
Contract with Customer, Sales Channel [Domain]
Direct Customers
Sales Channel, Directly to Consumer [Member]
Indirect Customers
Sales Channel, Through Intermediary [Member]
Other
Sales Channel, Other [Member]
Sales Channel, Other [Member]
Disaggregation of Revenue [Line Items]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer
Revenue from Contract with Customer, Excluding Assessed Tax
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
OTHER ASSETS
Other Assets Disclosure [Text Block]
Debt Disclosure [Abstract]
REVOLVING CREDIT ARRANGEMENT
Long-term Debt [Text Block]
Number of operating segments
Number of Operating Segments
Disposal Groups, Including Discontinued Operations [Table]
Disposal Groups, Including Discontinued Operations [Table]
Disposal Group Classification [Axis]
Disposal Group Classification [Axis]
Disposal Group Classification [Domain]
Disposal Group Classification [Domain]
Discontinued Operations, Disposed of by Sale
Discontinued Operations, Disposed of by Sale [Member]
Disposal Group Name [Axis]
Disposal Group Name [Axis]
Disposal Group Name [Domain]
Disposal Group Name [Domain]
GTX ECN
GTX ECN [Member]
GTX ECN [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal group, including discontinued operation, consideration
Disposal Group, Including Discontinued Operation, Consideration
Working capital adjustment
Disposal Group, Including Discontinued Operation, Working Capital Adjustment
Disposal Group, Including Discontinued Operation, Working Capital Adjustment
Noncontrolling Interest [Abstract]
Redeemable Noncontrolling Interest, by Legal Entity [Table]
Redeemable Noncontrolling Interest, by Legal Entity [Table]
Business Acquisition [Axis]
Business Acquisition [Axis]
Business Acquisition, Acquiree [Domain]
Business Acquisition, Acquiree [Domain]
Global Asset Advisors, LLC
Global Assets Advisors, LLC [Member]
Global Assets Advisors, LLC [Member]
Top Third Ag Marketing, LLC
Top Third Ag Marketing, LLC [Member]
Top Third Ag Marketing, LLC [Member]
Ownership [Axis]
Ownership [Axis]
Ownership [Domain]
Ownership [Domain]
Redeemable Noncontrolling Interest [Line Items]
Redeemable Noncontrolling Interest [Line Items]
Percentage of company acquired (as percent)
Business Acquisition, Percentage of Voting Interests Acquired
Redeemable noncontrolling interest retained by noncontrolling owners (as percent)
Redeemable Noncontrolling Interest,Ownership Percentage by Noncontrolling Owners
Redeemable Noncontrolling Interest,Ownership Percentage by Noncontrolling Owners
Noncontrolling interest by seller (as percent)
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners
Purchase of minority ownership interests
Payments to Acquire Additional Interest in Subsidiaries
Increase (Decrease) in Temporary Equity [Roll Forward]
Increase (Decrease) in Temporary Equity [Roll Forward]
Redeemable noncontrolling interest, beginning balance
Redeemable Noncontrolling Interest, Equity, Carrying Amount
Adjustment to the redemption value of non-controlling interests
Noncontrolling Interest, Change in Redemption Value
Net income attributable to non-controlling interests
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Noncontrolling Interest
Distributions to non-controlling interest holders
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders
Purchase of additional shares of non-controlling interest
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests
Redeemable noncontrolling interest, ending balance
Disaggregation of Revenue
Disaggregation of Revenue [Table Text Block]
INTANGIBLE ASSETS
Goodwill and Intangible Assets Disclosure [Text Block]
INCOME TAXES
Income Tax Disclosure [Text Block]
CONVERTIBLE SENIOR NOTES
Debt Disclosure [Text Block]
Related Party Transactions [Abstract]
RELATED PARTY TRANSACTIONS
Related Party Transactions Disclosure [Text Block]
Schedule of Long-term Debt Instruments [Table]
Schedule of Long-term Debt Instruments [Table]
Long-term Debt, Type [Axis]
Long-term Debt, Type [Axis]
Long-term Debt, Type [Domain]
Long-term Debt, Type [Domain]
Convertible Debt
Convertible Debt [Member]
Debt Instrument [Line Items]
Debt Instrument [Line Items]
Principal amount
Debt Instrument, Face Amount
Stated interest rate (as percent)
Debt Instrument, Interest Rate, Stated Percentage
Proceeds from note offering
Proceeds from Convertible Debt
Repurchase of convertible notes
Repayments of Convertible Debt
Loss on extinguishment of debt
Gain (Loss) on Extinguishment of Debt
Vendor and security deposits
Security Deposit
Income tax receivable
Income Taxes Receivable, Current
Deferred tax assets, net
Deferred Tax Assets, Net
GTX trade receivables
Accounts Receivable, Net
Customer debit positions
Accounts Receivable, Gross
Allowance on customer debit positions
Allowance for Doubtful Accounts Receivable
Prepaid assets
Prepaid Expense
Miscellaneous receivables
Other Assets, Miscellaneous
Deferred commitment fees
Accrued Fees and Other Revenue Receivable
Total other assets
Other Assets
Segment Reporting [Abstract]
Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table]
Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table]
Corporate and Other
Corporate, Non-Segment [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net revenue
Revenues
Employee compensation and benefits
Labor and Related Expense
Selling and marketing
Marketing and Advertising Expense
Referral fees
Sales Commissions and Fees
Other operating expenses
Other Cost and Expense, Operating
Segment profit (loss)
Gross Profit
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVES
Derivative Instruments and Hedging Activities Disclosure [Text Block]
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)
Common Stock, Par or Stated Value Per Share
Common stock, shares authorized (in shares)
Common Stock, Shares Authorized
Common stock, shares issued (in shares)
Common Stock, Shares, Issued
Common stock, shares outstanding (in shares)
Common Stock, Shares, Outstanding
Treasury stock, shares (in shares)
Treasury Stock, Shares
Revenue, Initial Application Period Cumulative Effect Transition [Table]
Revenue, Initial Application Period Cumulative Effect Transition [Table]
Initial Application Period Cumulative Effect Transition [Axis]
Initial Application Period Cumulative Effect Transition [Axis]
Initial Application Period Cumulative Effect Transition [Domain]
Initial Application Period Cumulative Effect Transition [Domain]
Difference between Revenue Guidance in Effect before and after Topic 606
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Adjustments for New Accounting Pronouncements [Axis]
Adjustments for New Accounting Pronouncements [Axis]
Type of Adoption [Domain]
Type of Adoption [Domain]
Accounting Standards Update 2014-09
Accounting Standards Update 2014-09 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Schedule of Liability and Equity Components of Convertible Debt
Convertible Debt [Table Text Block]
Schedule of Interest Expense
Schedule of Interest Expense [Table Text Block]
Schedule of Interest Expense [Table Text Block]
Credit Facility [Axis]
Credit Facility [Axis]
Credit Facility [Domain]
Credit Facility [Domain]
Revolving Credit Facility
Revolving Credit Facility [Member]
Line of Credit
Line of Credit [Member]
Range [Axis]
Range [Axis]
Range [Domain]
Range [Domain]
Maximum
Maximum [Member]
Minimum
Minimum [Member]
Term of credit facility
Debt Instrument, Term
Maximum amount under facility
Line of Credit Facility, Maximum Borrowing Capacity
Increase in borrowing capacity available
Line of Credit, Increase in Borrowing Capacity Available Upon Request
Line of Credit, Increase in Borrowing Capacity Available Upon Request
Commitment fee amount
Line of Credit Facility, Commitment Fee Amount
Line of credit outstanding
Long-term Line of Credit
Schedule of Finite-Lived Intangible Assets
Schedule of Finite-Lived Intangible Assets [Table Text Block]
Schedule of Goodwill
Schedule of Goodwill [Table Text Block]
SEGMENT INFORMATION
Segment Reporting Disclosure [Text Block]
DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION
Business Description and Basis of Presentation [Text Block]
Accounting Changes and Error Corrections [Abstract]
ACCOUNTING PRONOUNCEMENTS
New Accounting Pronouncements and Changes in Accounting Principles [Text Block]
Fair Value Disclosures [Abstract]
Carrying Amounts and Fair Values of Financial Instruments or Liabilities [Table]
Carrying Amounts And Fair Values Of Financial Instruments Or Liabilities [Table]
Carrying Amounts and Fair Values of Financial Instruments or Liabilities [Table]
Asset Class [Axis]
Asset Class [Axis]
Fair Value by Asset Class [Domain]
Asset Class [Domain]
Derivative Assets
Derivative Financial Instruments, Assets [Member]
Derivative Liabilities
Derivative Financial Instruments, Liabilities [Member]
Measurement Basis [Axis]
Measurement Basis [Axis]
Fair Value Measurement [Domain]
Fair Value Measurement [Domain]
Portion at Fair Value Measurement
Portion at Fair Value Measurement [Member]
Carrying Value
Reported Value Measurement [Member]
Fair Value
Estimate of Fair Value Measurement [Member]
Fair Value Hierarchy and NAV [Axis]
Fair Value Hierarchy and NAV [Axis]
Fair Value Hierarchy and NAV [Domain]
Fair Value Hierarchy and NAV [Domain]
Level 1
Fair Value, Inputs, Level 1 [Member]
Level 2
Fair Value, Inputs, Level 2 [Member]
Level 3
Fair Value, Inputs, Level 3 [Member]
Carrying Amounts and Fair Values of Financial Instruments or Liabilities [Line Items]
Carrying Amounts And Fair Values Of Financial Instruments Or Liabilities [Line Items]
Carrying Amounts and Fair Values of Financial Instruments or Liabilities [Line Items]
Financial Assets:
Assets, Fair Value Disclosure [Abstract]
Receivables from brokers
Receivables from Brokers-Dealers and Clearing Organizations
Financial Liabilities:
Liabilities, Fair Value Disclosure [Abstract]
Payables to customers
Derivative, Collateral, Obligation to Return Cash
Payables to brokers
Payables to Broker-Dealers and Clearing Organizations
Convertible senior notes
Notes Payable
Banking and Thrift [Abstract]
Regulatory Capital Subsidiaries Required to Maintain
Capital Requirements on Foreign Financial Institutions [Table Text Block]
Schedule of Segment Reporting Information, by Segment [Table]
Schedule of Segment Reporting Information, by Segment [Table]
Segment Reporting Information [Line Items]
Segment Reporting Information [Line Items]
Number of accessible global financial markets (more than)
Number of Accessible Global Financial Markets
Number of Accessible Global Financial Markets
Discontinued Operations and Disposal Groups [Abstract]
Disposal Groups, Including Discontinued Operations
Disposal Groups, Including Discontinued Operations [Table Text Block]
NON-CONTROLLING INTERESTS
Noncontrolling Interest Disclosure [Text Block]
Statement of Cash Flows [Abstract]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net income/(loss)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest
Adjustments to reconcile net income/(loss) to cash (used in)/provided by operating activities
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Loss/(gain) on foreign currency exchange rates
Foreign Currency Transaction Gain (Loss), before Tax
Depreciation and amortization
Depreciation, Depletion and Amortization
Deferred tax benefit
Deferred Income Tax Expense (Benefit)
Amortization of deferred financing costs
Amortization of Debt Issuance Costs
Bad debt provision
Provision for Doubtful Accounts
Convertible senior notes discount amortization
Amortization of Debt Discount (Premium)
Share-based compensation
Share-based Compensation
Loss on extinguishment of debt
Gain (Loss) on Extinguishment of Debt, before Write off of Debt Issuance Cost
Equity in net loss of affiliate
Income (Loss) from Equity Method Investments
Gain on sale of GTX
Gain (Loss) on Disposition of Business
Changes in operating assets and liabilities:
Increase (Decrease) in Operating Capital [Abstract]
Receivables from brokers
Increase (Decrease) in Receivables from Brokers-Dealers and Clearing Organizations
Other assets
Increase (Decrease) in Other Operating Assets
Payables to customers
Increase (Decrease) in Payables to Customers
Payables to brokers
Increase (Decrease) in Payables to Brokers
Increase (Decrease) in Payables to Brokers
Accrued compensation and benefits
Increase (Decrease) in Employee Related Liabilities
Accrued expenses and other liabilities
Increase (Decrease) in Accrued Liabilities and Other Operating Liabilities
Income tax payable
Increase (Decrease) in Income Taxes Payable
Net cash provided by/(used in) operating activities
Net Cash Provided by (Used in) Operating Activities
Cash provided by/(used in) operating activities - continuing operations
Net Cash Provided by (Used in) Operating Activities, Continuing Operations
Cash provided by/(used in) operating activities - discontinued operations
Cash Provided by (Used in) Operating Activities, Discontinued Operations
CASH FLOWS FROM INVESTING ACTIVITIES:
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchases of property and equipment
Payments to Acquire Property, Plant, and Equipment
Purchase of minority interest in GAA
Proceeds from sale of GTX
Proceeds from Divestiture of Businesses
Acquisition of FXCM assets
Payments to Acquire Intangible Assets
Net cash provided by/(used in) investing activities
Net Cash Provided by (Used in) Investing Activities
Cash used in investing activities - continuing operations
Net Cash Provided by (Used in) Investing Activities, Continuing Operations
Cash provided by/(used in) investing activities - discontinued operations
Cash Provided by (Used in) Investing Activities, Discontinued Operations
CASH FLOWS FROM FINANCING ACTIVITIES:
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from exercise of stock options
Proceeds from Stock Options Exercised
Proceeds from employee stock purchase plan
Proceeds from Stock Plans
Purchase of treasury stock
Payments for Repurchase of Common Stock
Dividend payments
Payments of Dividends
Distributions to non-controlling interest holders
Payments of Capital Distribution
Convertible note issuance, net
Repurchase of convertible notes
Net cash used in financing activities
Net Cash Provided by (Used in) Financing Activities
Effect of exchange rate changes on cash and cash equivalents
Effect of Exchange Rate on Cash and Cash Equivalents
NET INCREASE IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH — Beginning of period
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH — End of period
Cash and cash equivalents
Cash and Cash Equivalents, at Carrying Value
Cash and cash equivalents held for customers
Restricted Cash
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH — End of period
SUPPLEMENTARY DISCLOSURES OF CASH FLOW INFORMATION:
Supplemental Cash Flow Information [Abstract]
Cash paid during the year for:
Cash Paid During Period For [Abstract]
Cash Paid During Period For [Abstract]
Interest
Interest Paid, Excluding Capitalized Interest, Operating Activities
Income taxes
Income Taxes Paid, Net
Non-cash financing activities:
Noncash Investing Activities [Abstract]
Noncash Investing Activities [Abstract]
Adjustment to the redemption value of non-controlling interests
Subsequent Events [Abstract]
SUBSEQUENT EVENTS
Subsequent Events [Text Block]
Liability component - principal
Long-term Debt, Gross
Deferred bond discount
Debt Instrument, Unamortized Discount
Deferred financing cost
Debt Issuance Costs, Net
Liability component - net carrying value
Long-term Debt
Additional paid in capital
Debt Instrument, Convertible, Issuance Amount of Equity Component
Debt Instrument, Convertible, Issuance Amount of Equity Component
Discount attributable to equity
Debt Instrument, Convertible, Unamortized Discount of Equity Component
Debt Instrument, Convertible, Unamortized Discount of Equity Component
Equity component
Debt Instrument, Convertible, Issuance Amount of Equity Component, Net
Debt Instrument, Convertible, Issuance Amount of Equity Component, Net
Assets and Liabilities Measured at Fair Value on Recurring Basis
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]
Carrying Value and Fair Value and Fair Value Hierarchy Category of Financial Instruments Not Measured at Fair Value in Condensed Consolidated Statements of Financial Condition
Carrying Value And Fair Value Of Financial Instruments Disclosure [Table Text Block]
Carrying Value and Fair Value of Financial Instruments Disclosure [Table Text Block]
Schedule of Related Party Transactions, by Related Party [Table]
Schedule of Related Party Transactions, by Related Party [Table]
Related Party [Axis]
Related Party [Axis]
Related Party [Domain]
Related Party [Domain]
Management
Management [Member]
IPGL Limited
IPGL Limited [Member]
IPGL Limited [Member]
Related Party Transaction [Line Items]
Related Party Transaction [Line Items]
Payables to customers
Payables to Customers
Schedule of Intangible Assets by Major Class [Table]
Schedule Of Intangible Assets By Major Class [Table]
Schedule of Intangible Assets by Major Class [Table]
Finite-Lived Intangible Assets by Major Class [Axis]
Finite-Lived Intangible Assets by Major Class [Axis]
Finite-Lived Intangible Assets, Major Class Name [Domain]
Finite-Lived Intangible Assets, Major Class Name [Domain]
Customer lists
Customer Lists [Member]
Technology
Technology-Based Intangible Assets [Member]
Trademarks
Trademarks [Member]
Indefinite-lived Intangible Assets [Axis]
Indefinite-lived Intangible Assets [Axis]
Indefinite-lived Intangible Assets, Major Class Name [Domain]
Indefinite-lived Intangible Assets, Major Class Name [Domain]
Counterparty Name [Axis]
Counterparty Name [Axis]
Counterparty Name [Domain]
Counterparty Name [Domain]
Forex Capital Markets L.L.C.
Forex Capital Markets L.L.C. [Member]
Forex Capital Markets L.L.C. [Member]
Intangible Assets by Major Class [Line Items]
Intangible Assets By Major Class [Line Items]
Intangible Assets by Major Class [Line Items]
Finite-lived intangible assets, gross
Finite-Lived Intangible Assets, Gross
Accumulated Amortization
Finite-Lived Intangible Assets, Accumulated Amortization
Finite-lived intangible assets, net
Finite-Lived Intangible Assets, Net
Indefinite-lived intangible assets
Indefinite-lived Intangible Assets (Excluding Goodwill)
Total intangibles, gross
Intangible Assets Excluding Goodwill Gross
Intangible Assets Excluding Goodwill Gross
Intangible assets, net
Intangible Assets, Net (Excluding Goodwill)
Weighted average amortization period
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life
Amortization of Intangible Assets
Amortization of Intangible Assets
Payments to acquire intangible assets
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense
Depreciation, Depletion and Amortization, Nonproduction
Schedule of Other Assets
Schedule of Other Assets [Table Text Block]
Selected Financial Information by Segment
Schedule of Segment Reporting Information, by Segment [Table Text Block]
Reconciliation of Operating Segment Profit to Income Before Income Tax Expense
Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table Text Block]
EARNINGS/(LOSS) PER COMMON SHARE
Earnings Per Share [Text Block]
REGULATORY REQUIREMENTS
Regulatory Requirements Disclosure [Text Block]
Minimum regulatory capital required to be maintained as established by regulators in the United States and other jurisdictions, and capital levels maintained and in excess of the minimum capital requirements.
Statement [Table]
Statement [Table]
Product and Service [Axis]
Product and Service [Axis]
Product and Service [Domain]
Product and Service [Domain]
Retail revenue
Retail [Member]
Futures revenue
Futures Revenue [Member]
Futures Revenue [Member]
Other revenue
Product and Service, Other [Member]
Statement [Line Items]
Statement [Line Items]
REVENUE:
Revenues, Net of Interest Expense [Abstract]
Total non-interest revenue
Revenues, Excluding Interest and Dividends
Interest revenue
Interest Income, Operating
Interest expense
Interest Expense
Total net interest revenue
Interest Income (Expense), Net
Net revenue
Revenues, Net of Interest Expense
EXPENSES:
Costs and Expenses [Abstract]
Trading expenses
Trading Expenses And Commissions
Trading expense and commissions consists primarily of compensation paid to white label partners and introducing brokers.
General and administrative
General and Administrative Expense
Depreciation and amortization
Purchased intangible amortization
Communications and technology
Communications and Information Technology
Bad debt provision
Restructuring expenses
Restructuring Charges
Contingent provision
Gain (Loss) Related to Litigation Settlement
Impairment of investment
Other than Temporary Impairment Losses, Investments
Total operating expense
Costs and Expenses
OPERATING PROFIT
Operating Income (Loss)
Interest expense on long term borrowings
Interest Expense, Long-term Debt
Loss on extinguishment of debt
INCOME/(LOSS) BEFORE INCOME TAX EXPENSE/(BENEFIT)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest
Income tax (benefit)/expense
Equity in net loss of affiliate
Net income/(loss) from continuing operations
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest
Income from discontinued operations, including gain on sale of $69,439, net of income tax of $3,222
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest
NET INCOME/(LOSS)
Less income attributable to non-controlling interest
Net Income (Loss) Attributable to Noncontrolling Interest
NET INCOME/(LOSS) APPLICABLE TO GAIN CAPITAL HOLDINGS, INC.
Net Income (Loss) Attributable to Parent
Other comprehensive income:
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Foreign currency translation adjustment
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax
COMPREHENSIVE INCOME APPLICABLE TO GAIN CAPITAL HOLDINGS, INC.
Comprehensive Income (Loss), Net of Tax, Attributable to Parent
PROPERTY AND EQUIPMENT
Property, Plant and Equipment Disclosure [Text Block]
DISCONTINUED OPERATIONS
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]
Institutional revenue
Institutional Revenue [Member]
Institutional Revenue [Member]
Other revenue/(loss)
Gain on sale of discontinued operations
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax
Total non-interest revenue
Disposal Group, Including Discontinued Operation, Revenue
Interest revenue
Disposal Group, Including Discontinued Operation, Interest Income
Total net interest revenue
Net revenue
Disposal Group, Including Discontinued Operation, Revenue And Interest Income
Disposal Group, Including Discontinued Operation, Revenue And Interest Income
Employee compensation and benefits
Disposal Group, Including Discontinued Operation, Labor And Related Expense
Disposal Group, Including Discontinued Operation, Labor And Related Expense
Trading expenses
Disposal Group, Including Discontinued Operation, Trading Expenses And Commissions
Disposal Group, Including Discontinued Operation, Trading Expenses And Commissions
Other expenses
Disposal Group, Including Discontinued Operation, Other Expense
Total operating expense
Disposal Group, Including Discontinued Operation, Operating Expense
OPERATING PROFIT/(LOSS)
Disposal Group, Including Discontinued Operation, Operating Income (Loss)
Gain/(loss) on sale of discontinued operations
INCOME/(LOSS) BEFORE INCOME TAX EXPENSE/(BENEFIT)
Income tax expense/(benefit)
NET INCOME FROM DISCONTINUED OPERATIONS
Total assets of discontinued operations
Disposal Group, Including Discontinued Operation, Assets
Total liabilities of discontinued operations
Disposal Group, Including Discontinued Operation, Liabilities
Subsequent Event [Table]
Subsequent Event [Table]
Sale of Stock [Axis]
Sale of Stock [Axis]
Sale of Stock [Domain]
Sale of Stock [Domain]
Modified Dutch Auction
Modified Dutch Auction [Member]
Modified Dutch Auction [Member]
Subsequent Event Type [Axis]
Subsequent Event Type [Axis]
Subsequent Event Type [Domain]
Subsequent Event Type [Domain]
Subsequent event
Subsequent Event [Member]
Subsequent Event [Line Items]
Subsequent Event [Line Items]
Tender offer to purchase shares
Sale Of Stock, Consideration Offered Per Transaction
Sale Of Stock, Consideration Offered Per Transaction
Share price (usd per share)
Sale of Stock, Price Per Share Offered
Sale of Stock, Price Per Share Offered
Common stock dividend declared (usd per share)
Fair Values of Derivative Instruments
Schedule of Derivative Instruments [Table Text Block]
Notional Values of Derivative Instruments
Aggregate Notional Dollar Amount Of Derivatives [Table Text Block]
Aggregate Notional Dollar Amount Of Derivatives
Net Gains (Losses) With Respect to Derivative Instruments Which are Reflected in Trading Revenue
Schedule of Derivative Instruments Included in Trading Activities [Table Text Block]
Net income/(loss) from continuing operations
Less income attributable to non-controlling interests
Net income/(loss) from continuing operations
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent
Adjustment
Net income/(loss) available to GAIN common shareholders from continuing operations
Net Income Loss Available To Common Stockholders After Adjustments
Net Income Loss Available To Common Stockholders After Adjustments
Net income from discontinued operations
Weighted average common shares outstanding:
Weighted Average Number of Shares Outstanding, Diluted [Abstract]
Basic weighted average common shares outstanding
Weighted Average Number of Shares Outstanding, Basic
Effect of dilutive securities:
Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract]
Stock options (in shares)
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements
RSUs/RSAs (in shares)
Incremental Common Shares Attributable to Dilutive Effect of Nonvested Shares with Forfeitable Dividends
Diluted weighted average common shares outstanding
Weighted Average Number of Shares Outstanding, Diluted
Earnings/(loss) per common share:
Earnings Per Share, Basic and Diluted [Abstract]
Basic earnings/(loss) from continuing operations (usd per share)
Income (Loss) from Continuing Operations, Per Basic Share
Basic earnings from discontinued operations (usd per share)
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share
Diluted earnings/(loss) from continuing operations (usd per share)
Income (Loss) from Continuing Operations, Per Diluted Share
Diluted earnings from discontinued operations (usd per share)
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share
Schedule of Property and Equipment
Property, Plant and Equipment [Table Text Block]
Equity Components [Axis]
Equity Components [Axis]
Equity Component [Domain]
Equity Component [Domain]
Common Stock
Common Stock [Member]
Treasury Stock
Treasury Stock [Member]
Additional Paid-in Capital
Additional Paid-in Capital [Member]
Retained Earnings
Retained Earnings [Member]
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
BEGINNING BALANCE (in shares)
Shares, Outstanding
BEGINNING BALANCE
Stockholders' Equity Attributable to Parent
Net income (loss) applicable to Gain Capital Holdings, Inc.
Exercise of options (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period
Exercise of options
Stock Issued During Period, Value, Stock Options Exercised
Conversion of restricted stock into common stock (in shares)
Stock Issued During Period, Shares, Conversion of Units
Conversion of restricted stock into common stock
Stock Issued During Period, Value, Conversion of Units
Issuance of common stock for the employee stock purchase plan (in shares)
Stock Issued During Period, Shares, Employee Stock Purchase Plans
Issuance of common stock for the employee stock purchase plan
Stock Issued During Period, Value, Employee Stock Purchase Plan
Purchase of treasury stock (in shares)
Treasury Stock, Shares, Acquired
Purchase of treasury stock
Treasury Stock, Value, Acquired, Cost Method
Shares withheld for net settlements of share-based awards (in shares)
Shares Paid for Tax Withholding for Share Based Compensation
Shares withheld for net settlements of share-based awards
Adjustments Related to Tax Withholding for Share-based Compensation
Share-based compensation
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition
Recognition of debt discount on convertible notes
Adjustments to Additional Paid in Capital, Convertible Debt with Conversion Feature
Tax effect of debt discount on convertible notes
Adjustments To Additional Paid In Capital, Income Tax Effect From Convertible Debt With Conversion Feature
Adjustments To Additional Paid In Capital, Income Tax Effect From Convertible Debt With Conversion Feature
Repurchase of convertible notes
Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt
Adjustment to fair value of redeemable non-controlling interests
Dividends declared ($0.06 per share)
Dividends, Cash
Foreign currency translation adjustment
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax
ENDING BALANCE (in shares)
ENDING BALANCE
Derivative [Table]
Derivative [Table]
Derivative Instrument Risk [Axis]
Derivative Instrument [Axis]
Derivative Contract Type [Domain]
Derivative Contract [Domain]
Foreign currency exchange contracts
Foreign Exchange Contract [Member]
CFD contracts
Other Contract [Member]
Metal contracts
Commodity Contract [Member]
Derivative [Line Items]
Derivative [Line Items]
Net gains (losses) on derivative instruments
Derivative, Gain (Loss) on Derivative, Net
Net gains (losses) on derivative instruments, total
Gain (Loss) on Derivative Instruments, Net, Pretax
Position [Axis]
Position [Axis]
Position [Domain]
Position [Domain]
Total contracts in long positions
Long [Member]
Total contracts in short positions
Short [Member]
Notional amounts of derivative
Derivative, Notional Amount
Receivables from Brokerage Clients [Table]
Receivables From Brokerage Clients [Table]
Receivables from Brokerage Clients [Table]
Restricted Cash and Cash Equivalents [Axis]
Restricted Cash and Cash Equivalents [Axis]
Cash and Cash Equivalents [Domain]
Cash and Cash Equivalents [Domain]
Required collateral
Cash Collateral [Member]
Cash Collateral [Member]
Open foreign exchange positions
Open Position [Member]
Open Position [Member]
Receivables from Brokerage Clients [Line Items]
Receivables From Brokerage Clients [Line Items]
Receivables from Brokerage Clients [Line Items]
ASSETS:
Assets [Abstract]
Cash and cash equivalents held for customers
Restricted Cash and Cash Equivalents
Receivables from brokers
Property and equipment, net
Property, Plant and Equipment, Net
Intangible assets, net
Other assets
Total assets
Assets
LIABILITIES AND SHAREHOLDERS’ EQUITY:
Liabilities and Equity [Abstract]
Liabilities
Liabilities [Abstract]
Payables to customers
Accrued compensation and benefits
Employee-related Liabilities
Accrued expenses and other liabilities
Accrued Liabilities and Other Liabilities
Income tax payable
Accrued Income Taxes
Total liabilities
Liabilities
Commitments and contingent liabilities
Commitments and Contingencies
Redeemable non-controlling interests
Shareholders’ equity
Stockholders' Equity Attributable to Parent [Abstract]
Common stock ($0.00001 par value; 120 million shares authorized, 54,355,426 shares issued and 44,335,477 shares outstanding as of September 30, 2018; 120 million shares authorized, 53,612,340 shares issued and 45,152,299 shares outstanding as of December 31, 2017)
Common Stock, Value, Issued
Additional paid-in capital
Additional Paid in Capital, Common Stock
Retained earnings
Retained Earnings (Accumulated Deficit)
Accumulated other comprehensive loss
Accumulated Other Comprehensive Income (Loss), Net of Tax
Treasury stock, at cost (10,019,949 shares at September 30, 2018 and 8,460,041 at December 31, 2017)
Treasury Stock, Value
Total shareholders’ equity
Total liabilities and shareholders’ equity
Liabilities and Equity
SEGMENT PROFIT
FAIR VALUE MEASUREMENT
Fair Value Disclosures [Text Block]
Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table]
Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table]
Investment Type [Axis]
Investment Type [Axis]
Investments [Domain]
Investments [Domain]
Broker derivative contracts
Broker Open Contracts and Other Positions [Member]
Broker Open Contracts and Other Positions [Member]
Metals contracts
Balance Sheet Location [Axis]
Balance Sheet Location [Axis]
Balance Sheet Location [Domain]
Balance Sheet Location [Domain]
Receivables from brokers
Receivables from Brokers-Dealers and Clearing Organizations [Member]
Receivables from Brokers-Dealers and Clearing Organizations [Member]
Payables to customers
Payables to Customers [Member]
Payables to Customers [Member]
Derivatives, Fair Value [Line Items]
Derivatives, Fair Value [Line Items]
Gross amounts of assets for derivative open positions at fair value
Derivative Asset, Fair Value, Gross Asset
Cash Collateral
Derivative, Collateral, Right to Reclaim Cash
Cash Collateral
Gross amount of (liabilities) for derivative open positions at fair value
Derivative Asset, Fair Value, Gross Liability
Net amounts of assets/(liabilities) for derivative open positions at fair value
Derivative Asset, Fair Value, Amount Not Offset Against Collateral
Receivables from brokers
Payables to customers
Payables to brokers
Interest expense - stated coupon rate
Interest Expense, Debt, Excluding Amortization
Interest expense - amortization of deferred bond discount and costs
Total interest expense - convertible senior notes
Interest Expense, Debt
Commitments and Contingencies Disclosure [Abstract]
COMMITMENT AND CONTINGENCIES
Legal Matters and Contingencies [Text Block]
Fair Value Measurements, Recurring and Nonrecurring [Table]
Fair Value Measurements, Recurring and Nonrecurring [Table]
Measurement Frequency [Axis]
Measurement Frequency [Axis]
Fair Value, Measurement Frequency [Domain]
Fair Value, Measurement Frequency [Domain]
Recurring
Fair Value, Measurements, Recurring [Member]
Money market accounts
Money Market Funds [Member]
US treasury bills: U.S. government and agency securities
US Treasury and Government [Member]
Certificates of deposit
Certificates of Deposit [Member]
Other
Other Investments [Member]
Customer derivative contracts
Customer Open Contracts and Other Positions [Member]
Customer Open Contracts and Other Positions [Member]
Broker derivative contracts
Broker Derivative Contracts [Member]
Broker Derivative Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets
Assets, Fair Value Disclosure
Liabilities
Financial and Nonfinancial Liabilities, Fair Value Disclosure
Total
Fair Value, Net Asset (Liability)
Summary of redeemable noncontrolling interest treatment
Redeemable Noncontrolling Interest [Table Text Block]
Schedule of Property, Plant and Equipment [Table]
Property, Plant and Equipment [Table]
Property, Plant and Equipment, Type [Axis]
Property, Plant and Equipment, Type [Axis]
Property, Plant and Equipment, Type [Domain]
Property, Plant and Equipment, Type [Domain]
Software
Computer Software, Intangible Asset [Member]
Computer equipment
Computer Equipment [Member]
Leasehold improvements
Leasehold Improvements [Member]
Telephone equipment
Telecommunications Equipment Group [Member]
Telecommunications Equipment Group [Member]
Office equipment
Office Equipment [Member]
Furniture and fixtures
Furniture and Fixtures [Member]
Website development costs
Software Development [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment [Line Items]
Gross property and equipment
Property, Plant and Equipment, Gross
Less: Accumulated depreciation and amortization
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment
Property and equipment, net
Schedule Of Compliance With Regulatory Capital Requirements For Broker Dealer [Table]
Schedule Of Compliance With Regulatory Capital Requirements For Broker Dealer [Table]
Schedule Of Compliance With Regulatory Capital Requirements For Broker Dealer [Table]
Legal Entity [Axis]
Legal Entity [Axis]
Entity [Domain]
Entity [Domain]
GAIN Capital Group, LLC
Gain Capital Group Limited Liability Company [Member]
Gain Capital Group Limited Liability Company [Member]
GAIN Capital Securities, Inc.
Gain Capital Securities Incorporated [Member]
Gain Capital Securities Incorporated [Member]
GAIN Capital U.K., Ltd.
Gain Capital UK, Ltd. [Member]
Gain Capital UK, Ltd. [Member]
GAIN Capital Japan Co., Ltd.
Forex Com Japan Company Limited [Member]
Forex Com Japan Company Limited [Member]
GAIN Capital Australia, Pty. Ltd.
Gain Capital Australia Pty Ltd. [Member]
Gain Capital Australia Pty Ltd. [Member]
GAIN Capital-Forex.com Hong Kong, Ltd.
Gain Capital Forex Com Hong Kong Limited [Member]
Gain Capital Forex Com Hong Kong Limited [Member]
GAIN Global Markets, Inc.
Gain Global Markets Incorporated [Member]
Gain Global Markets Incorporated [Member]
GAIN Capital-Forex.com Canada, Ltd.
Gain Capital Forex Com Canada Limited [Member]
Gain Capital Forex Com Canada Limited [Member]
GAIN Capital Singapore Pte., Ltd.
Gain Capital Singapore Pte. Ltd. [Member]
Gain Capital Singapore Pte. Ltd. [Member]
Trade Facts, Ltd.
Trade Facts Ltd. [Member]
Trade Facts Ltd. [Member]
GTX SEF, LLC
GTX SEF, LLC [Member]
GTX SEF, LLC [Member]
Schedule Of Compliance With Regulatory Capital Requirements For Broker Dealer [Line Items]
Schedule Of Compliance With Regulatory Capital Requirements For Broker Dealer [Line Items]
Schedule Of Compliance With Regulatory Capital Requirements For Broker Dealer [Line Items]
Minimum Regulatory Capital Requirements
Capital Required for Capital Adequacy
Capital Levels Maintained
Capital Required to be Well Capitalized
Excess Net Capital
Excess Capital
Percent of Requirement Maintained
Excess Capital To Assets
Excess Capital to Assets
New Accounting Pronouncements or Change in Accounting Principle [Table]
New Accounting Pronouncements or Change in Accounting Principle [Table]
Accounting Standards Update 2016-18
Accounting Standards Update 2016-18 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by operating activities of continuing operations
RECEIVABLES FROM BROKERS
Due to and from Broker-Dealers and Clearing Organizations Disclosure [Text Block]