000100 - Document - Document and Entity Information link:presentationLink link:calculationLink link:definitionLink 010000 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) link:presentationLink link:calculationLink link:definitionLink 010100 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) link:presentationLink link:calculationLink link:definitionLink 020000 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (Unaudited) link:presentationLink link:calculationLink link:definitionLink 030000 - Statement - CONDENSED CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY (Unaudited) link:presentationLink link:calculationLink link:definitionLink 040000 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) link:presentationLink link:calculationLink link:definitionLink 060100 - Disclosure - BUSINESS AND ACCOUNTING POLICIES link:presentationLink link:calculationLink link:definitionLink 060200 - Disclosure - FINTECH MERGER link:presentationLink link:calculationLink link:definitionLink 060300 - Disclosure - REVENUE RECOGNITION STANDARD link:presentationLink link:calculationLink link:definitionLink 060400 - Disclosure - OTHER PREPAID EXPENSES AND CURRENT ASSETS link:presentationLink link:calculationLink link:definitionLink 060500 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS link:presentationLink link:calculationLink link:definitionLink 060600 - Disclosure - ACCRUED AND OTHER LIABILITIES link:presentationLink link:calculationLink link:definitionLink 060700 - Disclosure - DEBT link:presentationLink link:calculationLink link:definitionLink 060800 - Disclosure - FAIR VALUE MEASUREMENTS link:presentationLink link:calculationLink link:definitionLink 060900 - Disclosure - RELATED PARTY TRANSACTIONS link:presentationLink link:calculationLink link:definitionLink 061000 - Disclosure - STOCKHOLDERS' EQUITY AND SHARE-BASED COMPENSATION link:presentationLink link:calculationLink link:definitionLink 061100 - Disclosure - INCOME PER SHARE link:presentationLink link:calculationLink link:definitionLink 061200 - Disclosure - INCOME TAXES link:presentationLink link:calculationLink link:definitionLink 061300 - Disclosure - COMMITMENTS AND CONTINGENCIES link:presentationLink link:calculationLink link:definitionLink 070100 - Disclosure - BUSINESS AND ACCOUNTING POLICIES (Policies) link:presentationLink link:calculationLink link:definitionLink 080200 - Disclosure - FINTECH MERGER (Tables) link:presentationLink link:calculationLink link:definitionLink 080400 - Disclosure - OTHER PREPAID EXPENSES AND CURRENT ASSETS (Tables) link:presentationLink link:calculationLink link:definitionLink 080500 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS (Tables) link:presentationLink link:calculationLink link:definitionLink 080600 - Disclosure - ACCRUED AND OTHER LIABILITIES (Tables) link:presentationLink link:calculationLink link:definitionLink 080700 - Disclosure - DEBT (Tables) link:presentationLink link:calculationLink link:definitionLink 081000 - Disclosure - STOCKHOLDERS' EQUITY AND SHARE-BASED COMPENSATION (Tables) link:presentationLink link:calculationLink link:definitionLink 081100 - Disclosure - INCOME PER SHARE (Tables) link:presentationLink link:calculationLink link:definitionLink 081200 - Disclosure - INCOME TAXES (Tables) link:presentationLink link:calculationLink link:definitionLink 081300 - Disclosure - COMMITMENTS AND CONTINGENCIES (Tables) link:presentationLink link:calculationLink link:definitionLink 090100 - Disclosure - BUSINESS AND ACCOUNTING POLICIES (Details) link:presentationLink link:calculationLink link:definitionLink 090200 - Disclosure - FINTECH MERGER (Details) link:presentationLink link:calculationLink link:definitionLink 090300 - Disclosure - REVENUE RECOGNITION STANDARD (Details) link:presentationLink link:calculationLink link:definitionLink 090400 - Disclosure - OTHER PREPAID EXPENSES AND CURRENT ASSETS (Details) link:presentationLink link:calculationLink link:definitionLink 090500 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS (Details) link:presentationLink link:calculationLink link:definitionLink 090600 - Disclosure - ACCRUED AND OTHER LIABILITIES (Details) link:presentationLink link:calculationLink link:definitionLink 090700 - Disclosure - DEBT (Details) link:presentationLink link:calculationLink link:definitionLink 090900 - Disclosure - RELATED PARTY TRANSACTIONS (Details) link:presentationLink link:calculationLink link:definitionLink 091000 - Disclosure - STOCKHOLDERS' EQUITY AND SHARE-BASED COMPENSATION (Details) link:presentationLink link:calculationLink link:definitionLink 091002 - Disclosure - STOCKHOLDERS' EQUITY AND SHARE-BASED COMPENSATION, 2018 Omnibus Equity Compensation Plan (Details) link:presentationLink link:calculationLink link:definitionLink 091004 - Disclosure - STOCKHOLDERS' EQUITY AND SHARE-BASED COMPENSATION, Incentive Units (Details) link:presentationLink link:calculationLink link:definitionLink 091100 - Disclosure - INCOME PER SHARE (Details) link:presentationLink link:calculationLink link:definitionLink 091200 - Disclosure - INCOME TAXES (Details) link:presentationLink link:calculationLink link:definitionLink 091300 - Disclosure - COMMITMENTS AND CONTINGENCIES (Details) link:presentationLink link:calculationLink link:definitionLink