3.19.1 html 604 430 1 true 155 0 false 4 false false R1.htm 000 - Document - Document And Entity Information Sheet http://jmpg.com/20190331/role/statement-document-and-entity-information Document And Entity Information Cover 1 false false R2.htm 001 - Statement - Consolidated Statements of Financial Condition (Current Period Unaudited) Sheet http://jmpg.com/20190331/role/statement-consolidated-statements-of-financial-condition-current-period-unaudited Consolidated Statements of Financial Condition (Current Period Unaudited) Statements 2 false false R3.htm 002 - Statement - Consolidated Statements of Financial Condition (Current Period Unaudited) (Parentheticals) Sheet http://jmpg.com/20190331/role/statement-consolidated-statements-of-financial-condition-current-period-unaudited-parentheticals Consolidated Statements of Financial Condition (Current Period Unaudited) (Parentheticals) Statements 3 false false R4.htm 003 - Statement - Consolidated Statements of Operations (Unaudited) Sheet http://jmpg.com/20190331/role/statement-consolidated-statements-of-operations-unaudited Consolidated Statements of Operations (Unaudited) Statements 4 false false R5.htm 004 - Statement - Consolidated Statements of Comprehensive Income (Unaudited) Sheet http://jmpg.com/20190331/role/statement-consolidated-statements-of-comprehensive-income-unaudited Consolidated Statements of Comprehensive Income (Unaudited) Statements 5 false false R6.htm 005 - Statement - Consolidated Statements of Changes in Equity (Unaudited) Sheet http://jmpg.com/20190331/role/statement-consolidated-statements-of-changes-in-equity-unaudited Consolidated Statements of Changes in Equity (Unaudited) Statements 6 false false R7.htm 006 - Statement - Consolidated Statements of Cash Flows (Unaudited) Sheet http://jmpg.com/20190331/role/statement-consolidated-statements-of-cash-flows-unaudited Consolidated Statements of Cash Flows (Unaudited) Statements 7 false false R8.htm 007 - Disclosure - Note 1 - Organization and Description of Business Sheet http://jmpg.com/20190331/role/statement-note-1-organization-and-description-of-business Note 1 - Organization and Description of Business Notes 8 false false R9.htm 008 - Disclosure - Note 2 - Summary of Significant Accounting Policies Sheet http://jmpg.com/20190331/role/statement-note-2-summary-of-significant-accounting-policies Note 2 - Summary of Significant Accounting Policies Notes 9 false false R10.htm 009 - Disclosure - Note 3 - Recent Accounting Pronouncements Sheet http://jmpg.com/20190331/role/statement-note-3-recent-accounting-pronouncements Note 3 - Recent Accounting Pronouncements Notes 10 false false R11.htm 010 - Disclosure - Note 4 - Fair Value Measurements Sheet http://jmpg.com/20190331/role/statement-note-4-fair-value-measurements Note 4 - Fair Value Measurements Notes 11 false false R12.htm 011 - Disclosure - Note 5 - Loans Sheet http://jmpg.com/20190331/role/statement-note-5-loans Note 5 - Loans Notes 12 false false R13.htm 012 - Disclosure - Note 6 - Debt Sheet http://jmpg.com/20190331/role/statement-note-6-debt Note 6 - Debt Notes 13 false false R14.htm 013 - Disclosure - Note 7 - Asset-backed Securities Issued Sheet http://jmpg.com/20190331/role/statement-note-7-assetbacked-securities-issued Note 7 - Asset-backed Securities Issued Notes 14 false false R15.htm 014 - Disclosure - Note 8 - Leases Sheet http://jmpg.com/20190331/role/statement-note-8-leases Note 8 - Leases Notes 15 false false R16.htm 015 - Disclosure - Note 9 - Shareholders' Equity Sheet http://jmpg.com/20190331/role/statement-note-9-shareholders-equity Note 9 - Shareholders' Equity Notes 16 false false R17.htm 016 - Disclosure - Note 10 - Accumulated Other Comprehensive Income Sheet http://jmpg.com/20190331/role/statement-note-10-accumulated-other-comprehensive-income Note 10 - Accumulated Other Comprehensive Income Notes 17 false false R18.htm 017 - Disclosure - Note 11 - Share-based Compensation Sheet http://jmpg.com/20190331/role/statement-note-11-sharebased-compensation Note 11 - Share-based Compensation Notes 18 false false R19.htm 018 - Disclosure - Note 12 - Net Income Per Common Share Sheet http://jmpg.com/20190331/role/statement-note-12-net-income-per-common-share Note 12 - Net Income Per Common Share Notes 19 false false R20.htm 019 - Disclosure - Note 13 - ASC 606 Revenue from Contracts with Customers Sheet http://jmpg.com/20190331/role/statement-note-13-asc-606-revenue-from-contracts-with-customers Note 13 - ASC 606 Revenue from Contracts with Customers Notes 20 false false R21.htm 020 - Disclosure - Note 14 - Employee Benefits Sheet http://jmpg.com/20190331/role/statement-note-14-employee-benefits Note 14 - Employee Benefits Notes 21 false false R22.htm 021 - Disclosure - Note 15 - Income Taxes Sheet http://jmpg.com/20190331/role/statement-note-15-income-taxes Note 15 - Income Taxes Notes 22 false false R23.htm 022 - Disclosure - Note 16 - Commitments and Contingencies Sheet http://jmpg.com/20190331/role/statement-note-16-commitments-and-contingencies Note 16 - Commitments and Contingencies Notes 23 false false R24.htm 023 - Disclosure - Note 17 - Regulatory Requirements Sheet http://jmpg.com/20190331/role/statement-note-17-regulatory-requirements Note 17 - Regulatory Requirements Notes 24 false false R25.htm 024 - Disclosure - Note 18 - Related Party Transactions Sheet http://jmpg.com/20190331/role/statement-note-18-related-party-transactions Note 18 - Related Party Transactions Notes 25 false false R26.htm 025 - Disclosure - Note 19 - Guarantees Sheet http://jmpg.com/20190331/role/statement-note-19-guarantees Note 19 - Guarantees Notes 26 false false R27.htm 026 - Disclosure - Note 20 - Litigation Sheet http://jmpg.com/20190331/role/statement-note-20-litigation Note 20 - Litigation Notes 27 false false R28.htm 027 - Disclosure - Note 21 - Financial Instruments With Off-balance Sheet Risk, Credit Risk or Market Risk Sheet http://jmpg.com/20190331/role/statement-note-21-financial-instruments-with-offbalance-sheet-risk-credit-risk-or-market-risk Note 21 - Financial Instruments With Off-balance Sheet Risk, Credit Risk or Market Risk Notes 28 false false R29.htm 028 - Disclosure - Note 22 - Business Segments Sheet http://jmpg.com/20190331/role/statement-note-22-business-segments Note 22 - Business Segments Notes 29 false false R30.htm 029 - Disclosure - Note 23 - Nonconsolidated Variable Interest Entities Sheet http://jmpg.com/20190331/role/statement-note-23-nonconsolidated-variable-interest-entities- Note 23 - Nonconsolidated Variable Interest Entities Notes 30 false false R31.htm 030 - Disclosure - Note 24 - Consolidating Financial Statements Sheet http://jmpg.com/20190331/role/statement-note-24-consolidating-financial-statements Note 24 - Consolidating Financial Statements Notes 31 false false R32.htm 031 - Disclosure - Note 25 - Subsequent Events Sheet http://jmpg.com/20190331/role/statement-note-25-subsequent-events Note 25 - Subsequent Events Notes 32 false false R33.htm 032 - Disclosure - Significant Accounting Policies (Policies) Sheet http://jmpg.com/20190331/role/statement-significant-accounting-policies-policies Significant Accounting Policies (Policies) Policies http://jmpg.com/20190331/role/statement-note-2-summary-of-significant-accounting-policies 33 false false R34.htm 033 - Disclosure - Note 1 - Organization and Description of Business (Tables) Sheet http://jmpg.com/20190331/role/statement-note-1-organization-and-description-of-business-tables Note 1 - Organization and Description of Business (Tables) Tables http://jmpg.com/20190331/role/statement-note-1-organization-and-description-of-business 34 false false R35.htm 034 - Disclosure - Note 4 - Fair Value Measurements (Tables) Sheet http://jmpg.com/20190331/role/statement-note-4-fair-value-measurements-tables Note 4 - Fair Value Measurements (Tables) Tables http://jmpg.com/20190331/role/statement-note-4-fair-value-measurements 35 false false R36.htm 035 - Disclosure - Note 5 - Loans (Tables) Sheet http://jmpg.com/20190331/role/statement-note-5-loans-tables Note 5 - Loans (Tables) Tables http://jmpg.com/20190331/role/statement-note-5-loans 36 false false R37.htm 036 - Disclosure - Note 6 - Debt (Tables) Sheet http://jmpg.com/20190331/role/statement-note-6-debt-tables Note 6 - Debt (Tables) Tables http://jmpg.com/20190331/role/statement-note-6-debt 37 false false R38.htm 037 - Disclosure - Note 7 - Asset-backed Securities Issued (Tables) Sheet http://jmpg.com/20190331/role/statement-note-7-assetbacked-securities-issued-tables Note 7 - Asset-backed Securities Issued (Tables) Tables http://jmpg.com/20190331/role/statement-note-7-assetbacked-securities-issued 38 false false R39.htm 038 - Disclosure - Note 8 - Leases (Tables) Sheet http://jmpg.com/20190331/role/statement-note-8-leases-tables Note 8 - Leases (Tables) Tables http://jmpg.com/20190331/role/statement-note-8-leases 39 false false R40.htm 039 - Disclosure - Note 10 - Accumulated Other Comprehensive Income (Tables) Sheet http://jmpg.com/20190331/role/statement-note-10-accumulated-other-comprehensive-income-tables Note 10 - Accumulated Other Comprehensive Income (Tables) Tables http://jmpg.com/20190331/role/statement-note-10-accumulated-other-comprehensive-income 40 false false R41.htm 040 - Disclosure - Note 11 - Share-based Compensation (Tables) Sheet http://jmpg.com/20190331/role/statement-note-11-sharebased-compensation-tables Note 11 - Share-based Compensation (Tables) Tables http://jmpg.com/20190331/role/statement-note-11-sharebased-compensation 41 false false R42.htm 041 - Disclosure - Note 12 - Net Income Per Common Share (Tables) Sheet http://jmpg.com/20190331/role/statement-note-12-net-income-per-common-share-tables Note 12 - Net Income Per Common Share (Tables) Tables http://jmpg.com/20190331/role/statement-note-12-net-income-per-common-share 42 false false R43.htm 042 - Disclosure - Note 13 - ASC 606 Revenue from Contracts with Customers (Tables) Sheet http://jmpg.com/20190331/role/statement-note-13-asc-606-revenue-from-contracts-with-customers-tables Note 13 - ASC 606 Revenue from Contracts with Customers (Tables) Tables http://jmpg.com/20190331/role/statement-note-13-asc-606-revenue-from-contracts-with-customers 43 false false R44.htm 043 - Disclosure - Note 22 - Business Segments (Tables) Sheet http://jmpg.com/20190331/role/statement-note-22-business-segments-tables Note 22 - Business Segments (Tables) Tables http://jmpg.com/20190331/role/statement-note-22-business-segments 44 false false R45.htm 044 - Disclosure - Note 23 - Nonconsolidated Variable Interest Entities (Tables) Sheet http://jmpg.com/20190331/role/statement-note-23-nonconsolidated-variable-interest-entities-tables Note 23 - Nonconsolidated Variable Interest Entities (Tables) Tables http://jmpg.com/20190331/role/statement-note-23-nonconsolidated-variable-interest-entities- 45 false false R46.htm 045 - Disclosure - Note 24 - Consolidating Financial Statements (Tables) Sheet http://jmpg.com/20190331/role/statement-note-24-consolidating-financial-statements-tables Note 24 - Consolidating Financial Statements (Tables) Tables http://jmpg.com/20190331/role/statement-note-24-consolidating-financial-statements 46 false false R47.htm 046 - Disclosure - Note 1 - Organization and Description of Business (Details Textual) Sheet http://jmpg.com/20190331/role/statement-note-1-organization-and-description-of-business-details-textual Note 1 - Organization and Description of Business (Details Textual) Details http://jmpg.com/20190331/role/statement-note-1-organization-and-description-of-business-tables 47 false false R48.htm 047 - Disclosure - Note 1 - Organization and Description of Business - Deconsolidation of the CLO's and JMPCA (Details) Sheet http://jmpg.com/20190331/role/statement-note-1-organization-and-description-of-business-deconsolidation-of-the-clos-and-jmpca-details Note 1 - Organization and Description of Business - Deconsolidation of the CLO's and JMPCA (Details) Details 48 false false R49.htm 048 - Disclosure - Note 2 - Summary of Significant Accounting Policies (Details Textual) Sheet http://jmpg.com/20190331/role/statement-note-2-summary-of-significant-accounting-policies-details-textual Note 2 - Summary of Significant Accounting Policies (Details Textual) Details 49 false false R50.htm 049 - Disclosure - Note 3 - Recent Accounting Pronouncements (Details Textual) Sheet http://jmpg.com/20190331/role/statement-note-3-recent-accounting-pronouncements-details-textual Note 3 - Recent Accounting Pronouncements (Details Textual) Details http://jmpg.com/20190331/role/statement-note-3-recent-accounting-pronouncements 50 false false R51.htm 050 - Disclosure - Note 4 - Fair Value Measurements (Details Textual) Sheet http://jmpg.com/20190331/role/statement-note-4-fair-value-measurements-details-textual Note 4 - Fair Value Measurements (Details Textual) Details http://jmpg.com/20190331/role/statement-note-4-fair-value-measurements-tables 51 false false R52.htm 051 - Disclosure - Note 4 - Fair Value Measurements - Fair Value of Financial Instruments (Details) Sheet http://jmpg.com/20190331/role/statement-note-4-fair-value-measurements-fair-value-of-financial-instruments-details Note 4 - Fair Value Measurements - Fair Value of Financial Instruments (Details) Details 52 false false R53.htm 052 - Disclosure - Note 4 - Fair Value Measurements - Fair Value of Assets and Liabilities on a Recurring Basis (Details) Sheet http://jmpg.com/20190331/role/statement-note-4-fair-value-measurements-fair-value-of-assets-and-liabilities-on-a-recurring-basis-details Note 4 - Fair Value Measurements - Fair Value of Assets and Liabilities on a Recurring Basis (Details) Details 53 false false R54.htm 053 - Disclosure - Note 4 - Fair Value Measurements - Available-for-sale Securities (Details) Sheet http://jmpg.com/20190331/role/statement-note-4-fair-value-measurements-availableforsale-securities-details Note 4 - Fair Value Measurements - Available-for-sale Securities (Details) Details 54 false false R55.htm 054 - Disclosure - Note 4 - Fair Value Measurements - Held-to-maturity Securities (Details) Sheet http://jmpg.com/20190331/role/statement-note-4-fair-value-measurements-heldtomaturity-securities-details Note 4 - Fair Value Measurements - Held-to-maturity Securities (Details) Details 55 false false R56.htm 055 - Disclosure - Note 4 - Fair Value Measurements - Securities By Contractual Maturity (Details) Sheet http://jmpg.com/20190331/role/statement-note-4-fair-value-measurements-securities-by-contractual-maturity-details Note 4 - Fair Value Measurements - Securities By Contractual Maturity (Details) Details 56 false false R57.htm 056 - Disclosure - Note 4 - Fair Value Measurements - Continuous Unrealized Loss Positions (Details) Sheet http://jmpg.com/20190331/role/statement-note-4-fair-value-measurements-continuous-unrealized-loss-positions-details Note 4 - Fair Value Measurements - Continuous Unrealized Loss Positions (Details) Details 57 false false R58.htm 057 - Disclosure - Note 4 - Fair Value Measurements - Changes in Level 3 Assets Measured at Fair Value (Details) Sheet http://jmpg.com/20190331/role/statement-note-4-fair-value-measurements-changes-in-level-3-assets-measured-at-fair-value-details Note 4 - Fair Value Measurements - Changes in Level 3 Assets Measured at Fair Value (Details) Details 58 false false R59.htm 058 - Disclosure - Note 4 - Fair Value Measurements - Significant Unobservable Inputs Used in Fair Value Measurements (Details) Sheet http://jmpg.com/20190331/role/statement-note-4-fair-value-measurements-significant-unobservable-inputs-used-in-fair-value-measurements-details Note 4 - Fair Value Measurements - Significant Unobservable Inputs Used in Fair Value Measurements (Details) Details 59 false false R60.htm 059 - Disclosure - Note 5 - Loans (Details Textual) Sheet http://jmpg.com/20190331/role/statement-note-5-loans-details-textual Note 5 - Loans (Details Textual) Details http://jmpg.com/20190331/role/statement-note-5-loans-tables 60 false false R61.htm 060 - Disclosure - Note 5 - Loans - Loans Collateralizing Asset-Backed Securities Issued, Allowance for Loan Losses (Details) Sheet http://jmpg.com/20190331/role/statement-note-5-loans-loans-collateralizing-assetbacked-securities-issued-allowance-for-loan-losses-details Note 5 - Loans - Loans Collateralizing Asset-Backed Securities Issued, Allowance for Loan Losses (Details) Details 61 false false R62.htm 061 - Disclosure - Note 5 - Loans - Loans Collateralizing Asset-Backed Securities Issued, Schedule of Impaired Financing Receivable (Details) Sheet http://jmpg.com/20190331/role/statement-note-5-loans-loans-collateralizing-assetbacked-securities-issued-schedule-of-impaired-financing-receivable-details Note 5 - Loans - Loans Collateralizing Asset-Backed Securities Issued, Schedule of Impaired Financing Receivable (Details) Details 62 false false R63.htm 062 - Disclosure - Note 5 - Loans - Credit Quality of Loans (Details) Sheet http://jmpg.com/20190331/role/statement-note-5-loans-credit-quality-of-loans-details Note 5 - Loans - Credit Quality of Loans (Details) Details 63 false false R64.htm 063 - Disclosure - Note 5 - Loans - Loans Held for Investment, Allowance for Loan Losses (Details) Sheet http://jmpg.com/20190331/role/statement-note-5-loans-loans-held-for-investment-allowance-for-loan-losses-details Note 5 - Loans - Loans Held for Investment, Allowance for Loan Losses (Details) Details 64 false false R65.htm 064 - Disclosure - Note 5 - Loans - Loans Held for Investment, Schedule of Impaired Financing Receivable (Details) Sheet http://jmpg.com/20190331/role/statement-note-5-loans-loans-held-for-investment-schedule-of-impaired-financing-receivable-details Note 5 - Loans - Loans Held for Investment, Schedule of Impaired Financing Receivable (Details) Details 65 false false R66.htm 065 - Disclosure - Note 5 - Loans - Loans Held for Investment, Credit Quality of Loans (Details) Sheet http://jmpg.com/20190331/role/statement-note-5-loans-loans-held-for-investment-credit-quality-of-loans-details Note 5 - Loans - Loans Held for Investment, Credit Quality of Loans (Details) Details 66 false false R67.htm 066 - Disclosure - Note 6 - Debt (Details Textual) Sheet http://jmpg.com/20190331/role/statement-note-6-debt-details-textual Note 6 - Debt (Details Textual) Details http://jmpg.com/20190331/role/statement-note-6-debt-tables 67 false false R68.htm 067 - Disclosure - Note 6 - Debt - Debt Issuance Costs (Details) Sheet http://jmpg.com/20190331/role/statement-note-6-debt-debt-issuance-costs-details Note 6 - Debt - Debt Issuance Costs (Details) Details 68 false false R69.htm 068 - Disclosure - Note 6 - Debt - Debt Issuance Costs (Details) (Parentheticals) Sheet http://jmpg.com/20190331/role/statement-note-6-debt-debt-issuance-costs-details-parentheticals Note 6 - Debt - Debt Issuance Costs (Details) (Parentheticals) Details 69 false false R70.htm 069 - Disclosure - Note 6 - Debt - Summary of Scheduled Principal Payments of Debt Obligations (Details) Sheet http://jmpg.com/20190331/role/statement-note-6-debt-summary-of-scheduled-principal-payments-of-debt-obligations-details Note 6 - Debt - Summary of Scheduled Principal Payments of Debt Obligations (Details) Details 70 false false R71.htm 070 - Disclosure - Note 6 - Debt - Notes Payable, Lines of Credit and Credit Facilities (Details) Notes http://jmpg.com/20190331/role/statement-note-6-debt-notes-payable-lines-of-credit-and-credit-facilities-details Note 6 - Debt - Notes Payable, Lines of Credit and Credit Facilities (Details) Details 71 false false R72.htm 071 - Disclosure - Note 6 - Debt - Notes Payable, Lines of Credit and Credit Facilities (Details) (Parentheticals) Notes http://jmpg.com/20190331/role/statement-note-6-debt-notes-payable-lines-of-credit-and-credit-facilities-details-parentheticals Note 6 - Debt - Notes Payable, Lines of Credit and Credit Facilities (Details) (Parentheticals) Details 72 false false R73.htm 072 - Disclosure - Note 7 - Asset-backed Securities Issued (Details Textual) Sheet http://jmpg.com/20190331/role/statement-note-7-assetbacked-securities-issued-details-textual Note 7 - Asset-backed Securities Issued (Details Textual) Details http://jmpg.com/20190331/role/statement-note-7-assetbacked-securities-issued-tables 73 false false R74.htm 073 - Disclosure - Note 7 - Asset-backed Securities Issued - Asset-backed Securities Issued - CLO III, CLO IV, and CLO V (Details) Sheet http://jmpg.com/20190331/role/statement-note-7-assetbacked-securities-issued-assetbacked-securities-issued-clo-iii-clo-iv-and-clo-v-details Note 7 - Asset-backed Securities Issued - Asset-backed Securities Issued - CLO III, CLO IV, and CLO V (Details) Details 74 false false R75.htm 074 - Disclosure - Note 8 - Leases (Details Textual) Sheet http://jmpg.com/20190331/role/statement-note-8-leases-details-textual Note 8 - Leases (Details Textual) Details http://jmpg.com/20190331/role/statement-note-8-leases-tables 75 false false R76.htm 075 - Disclosure - Note 8 - Leases - Lease Information (Details) Sheet http://jmpg.com/20190331/role/statement-note-8-leases-lease-information-details Note 8 - Leases - Lease Information (Details) Details 76 false false R77.htm 076 - Disclosure - Note 8 - Leases - Minimum Future Lease Payments (Details) Sheet http://jmpg.com/20190331/role/statement-note-8-leases-minimum-future-lease-payments-details Note 8 - Leases - Minimum Future Lease Payments (Details) Details 77 false false R78.htm 077 - Disclosure - Note 9 - Shareholders' Equity (Details Textual) Sheet http://jmpg.com/20190331/role/statement-note-9-shareholders-equity-details-textual Note 9 - Shareholders' Equity (Details Textual) Details http://jmpg.com/20190331/role/statement-note-9-shareholders-equity 78 false false R79.htm 078 - Disclosure - Note 10 - Accumulated Other Comprehensive Income - Unrealized Gains (Losses) of Accumulated Other Comprehensive Losses (Details) Sheet http://jmpg.com/20190331/role/statement-note-10-accumulated-other-comprehensive-income-unrealized-gains-losses-of-accumulated-other-comprehensive-losses-details Note 10 - Accumulated Other Comprehensive Income - Unrealized Gains (Losses) of Accumulated Other Comprehensive Losses (Details) Details 79 false false R80.htm 079 - Disclosure - Note 11 - Share-based Compensation (Details Textual) Sheet http://jmpg.com/20190331/role/statement-note-11-sharebased-compensation-details-textual Note 11 - Share-based Compensation (Details Textual) Details http://jmpg.com/20190331/role/statement-note-11-sharebased-compensation-tables 80 false false R81.htm 080 - Disclosure - Note 11 - Share-based Compensation - Stock Option Activity (Details) Sheet http://jmpg.com/20190331/role/statement-note-11-sharebased-compensation-stock-option-activity-details Note 11 - Share-based Compensation - Stock Option Activity (Details) Details 81 false false R82.htm 081 - Disclosure - Note 11 - Share-based Compensation - Stock Options Outstanding and Exercisable (Details) Sheet http://jmpg.com/20190331/role/statement-note-11-sharebased-compensation-stock-options-outstanding-and-exercisable-details Note 11 - Share-based Compensation - Stock Options Outstanding and Exercisable (Details) Details 82 false false R83.htm 082 - Disclosure - Note 11 - Share-based Compensation - Restricted Stock Units Activity (RSUs) (Details) Sheet http://jmpg.com/20190331/role/statement-note-11-sharebased-compensation-restricted-stock-units-activity-rsus-details Note 11 - Share-based Compensation - Restricted Stock Units Activity (RSUs) (Details) Details 83 false false R84.htm 083 - Disclosure - Note 11 - Share-based Compensation - SARs Activity (Stock Appreciation Rights (SARs) (Details) Sheet http://jmpg.com/20190331/role/statement-note-11-sharebased-compensation-sars-activity-stock-appreciation-rights-sars-details Note 11 - Share-based Compensation - SARs Activity (Stock Appreciation Rights (SARs) (Details) Details 84 false false R85.htm 084 - Disclosure - Note 11 - Share-based Compensation - SARs Outstanding (Details) Sheet http://jmpg.com/20190331/role/statement-note-11-sharebased-compensation-sars-outstanding-details Note 11 - Share-based Compensation - SARs Outstanding (Details) Details 85 false false R86.htm 085 - Disclosure - Note 12 - Net Income Per Common Share - Earnings Per Share, Basic and Diluted (Details) Sheet http://jmpg.com/20190331/role/statement-note-12-net-income-per-common-share-earnings-per-share-basic-and-diluted-details Note 12 - Net Income Per Common Share - Earnings Per Share, Basic and Diluted (Details) Details 86 false false R87.htm 086 - Disclosure - Note 13 - ASC 606 Revenue from contracts with customers - Disaggregation of Revenues (Details) Sheet http://jmpg.com/20190331/role/statement-note-13-asc-606-revenue-from-contracts-with-customers-disaggregation-of-revenues-details Note 13 - ASC 606 Revenue from contracts with customers - Disaggregation of Revenues (Details) Details 87 false false R88.htm 087 - Disclosure - Note 14 - Employee Benefits (Details Textual) Sheet http://jmpg.com/20190331/role/statement-note-14-employee-benefits-details-textual Note 14 - Employee Benefits (Details Textual) Details http://jmpg.com/20190331/role/statement-note-14-employee-benefits 88 false false R89.htm 088 - Disclosure - Note 15 - Income Taxes (Details Textual) Sheet http://jmpg.com/20190331/role/statement-note-15-income-taxes-details-textual Note 15 - Income Taxes (Details Textual) Details http://jmpg.com/20190331/role/statement-note-15-income-taxes 89 false false R90.htm 089 - Disclosure - Note 16 - Commitments and Contingencies (Details Textual) Sheet http://jmpg.com/20190331/role/statement-note-16-commitments-and-contingencies-details-textual Note 16 - Commitments and Contingencies (Details Textual) Details http://jmpg.com/20190331/role/statement-note-16-commitments-and-contingencies 90 false false R91.htm 090 - Disclosure - Note 17 - Regulatory Requirements (Details Textual) Sheet http://jmpg.com/20190331/role/statement-note-17-regulatory-requirements-details-textual Note 17 - Regulatory Requirements (Details Textual) Details http://jmpg.com/20190331/role/statement-note-17-regulatory-requirements 91 false false R92.htm 091 - Disclosure - Note 18 - Related Party Transactions (Details Textual) Sheet http://jmpg.com/20190331/role/statement-note-18-related-party-transactions-details-textual Note 18 - Related Party Transactions (Details Textual) Details http://jmpg.com/20190331/role/statement-note-18-related-party-transactions 92 false false R93.htm 092 - Disclosure - Note 19 - Guarantees (Details Textual) Sheet http://jmpg.com/20190331/role/statement-note-19-guarantees-details-textual Note 19 - Guarantees (Details Textual) Details http://jmpg.com/20190331/role/statement-note-19-guarantees 93 false false R94.htm 093 - Disclosure - Note 21 - Financial Instruments With Off-balance Sheet Risk, Credit Risk or Market Risk (Details Textual) Sheet http://jmpg.com/20190331/role/statement-note-21-financial-instruments-with-offbalance-sheet-risk-credit-risk-or-market-risk-details-textual Note 21 - Financial Instruments With Off-balance Sheet Risk, Credit Risk or Market Risk (Details Textual) Details http://jmpg.com/20190331/role/statement-note-21-financial-instruments-with-offbalance-sheet-risk-credit-risk-or-market-risk 94 false false R95.htm 094 - Disclosure - Note 22 - Business Segments (Details Textual) Sheet http://jmpg.com/20190331/role/statement-note-22-business-segments-details-textual Note 22 - Business Segments (Details Textual) Details http://jmpg.com/20190331/role/statement-note-22-business-segments-tables 95 false false R96.htm 095 - Disclosure - Note 22 - Business Segments - Segment Operating Results (Details) Sheet http://jmpg.com/20190331/role/statement-note-22-business-segments-segment-operating-results-details Note 22 - Business Segments - Segment Operating Results (Details) Details 96 false false R97.htm 096 - Disclosure - Note 22 - Business Segments - Reconciling Operating Pre-tax Net Income to Consolidated Net Income (Details) Sheet http://jmpg.com/20190331/role/statement-note-22-business-segments-reconciling-operating-pretax-net-income-to-consolidated-net-income-details Note 22 - Business Segments - Reconciling Operating Pre-tax Net Income to Consolidated Net Income (Details) Details 97 false false R98.htm 097 - Disclosure - Note 23 - Nonconsolidated Variable Interest Entities - VIE Equity Investments and Receivables (Details) Sheet http://jmpg.com/20190331/role/statement-note-23-nonconsolidated-variable-interest-entities-vie-equity-investments-and-receivables-details Note 23 - Nonconsolidated Variable Interest Entities - VIE Equity Investments and Receivables (Details) Details 98 false false R99.htm 098 - Disclosure - Note 24 - Consolidating Financial Statements - Condensed Consolidating Balance Sheet (Details) Sheet http://jmpg.com/20190331/role/statement-note-24-consolidating-financial-statements-condensed-consolidating-balance-sheet-details Note 24 - Consolidating Financial Statements - Condensed Consolidating Balance Sheet (Details) Details 99 false false R100.htm 099 - Disclosure - Note 24 - Consolidating Financial Statements - Condensed Consolidating Income Statement (Details) Sheet http://jmpg.com/20190331/role/statement-note-24-consolidating-financial-statements-condensed-consolidating-income-statement-details Note 24 - Consolidating Financial Statements - Condensed Consolidating Income Statement (Details) Details 100 false false R101.htm 100 - Disclosure - Note 24 - Consolidating Financial Statements - Condensed Consolidating Cash Flows (Details) Sheet http://jmpg.com/20190331/role/statement-note-24-consolidating-financial-statements-condensed-consolidating-cash-flows-details Note 24 - Consolidating Financial Statements - Condensed Consolidating Cash Flows (Details) Details 101 false false R102.htm 101 - Disclosure - Note 25 - Subsequent Events (Details Textual) Sheet http://jmpg.com/20190331/role/statement-note-25-subsequent-events-details-textual Note 25 - Subsequent Events (Details Textual) Details http://jmpg.com/20190331/role/statement-note-25-subsequent-events 102 false false All Reports Book All Reports jmp-20190331.xml jmp-20190331.xsd jmp-20190331_cal.xml jmp-20190331_def.xml jmp-20190331_lab.xml jmp-20190331_pre.xml http://fasb.org/us-gaap/2019-01-31 http://fasb.org/srt/2019-01-31 http://xbrl.sec.gov/dei/2018-01-31 true true