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Assets and Liabilities, at Fair Value - Financial Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Millions | Mar. 31, 2022 | Sep. 30, 2021
--- | --- | ---
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Cash and cash equivalents | $ 190.7 | $ 14.1
Securities and other assets segregated under federal and other regulations | 2,766.5 | 2,274.4
Financial instruments owned | 4,156.2 | 4,354.6
Physical commodities inventory | 547.4 | 447.5
Accounts payable and other accrued liabilities - contingent liabilities | 335.2 | 305.1
Payable to broker-dealers, clearing organizations and counterparties | 519.9 | 613.5
Financial instruments sold, not yet purchased | 2,781.8 | 1,771.2
Fair Value, Recurring |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Cash and cash equivalents | 50.1 | 20.8
Securities and other assets segregated under federal and other regulations | 190.7 | 14.1
Deposits with and receivables from broker-dealers, clearing organizations and counterparties, net | 746.8 | 1,070.6
Receivables from clients, net - Derivatives | (15.5) | 2.6
Financial instruments owned | 4,156.2 | 4,354.6
Total assets at fair value | 5,490.7 | 5,822.6
Payables to clients - Derivatives | (546.1) | 291.5
Total liabilities at fair value | 2,289.2 | 2,078.2
Fair Value, Recurring | TBA and forward settling securities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Payable to broker-dealers, clearing organizations and counterparties | 62.3 | 12.7
Fair Value, Recurring | Derivatives |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Payable to broker-dealers, clearing organizations and counterparties | (10.3) | 0.0
Fair Value, Recurring | Payables to Broker-dealers, Clearing Organizations and Counterparties |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Payable to broker-dealers, clearing organizations and counterparties | 52.0 | 12.7
Fair Value, Recurring | Contingent Consideration |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Accounts payable and other accrued liabilities - contingent liabilities | 1.5 | 2.8
Fair Value, Recurring | Physical commodities inventory |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Physical commodities inventory | 362.4 | 359.9
Fair Value, Recurring | Equity securities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 1,236.0 | 527.0
Financial instruments sold, not yet purchased | 1,155.1 | 436.1
Fair Value, Recurring | Corporate and municipal bonds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 120.3 | 150.8
Financial instruments sold, not yet purchased | 78.2 | 51.1
Fair Value, Recurring | U.S. Treasury obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 176.2 | 433.1
Financial instruments sold, not yet purchased | 1,018.1 | 851.2
Fair Value, Recurring | U.S. government agency obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 342.1 | 327.6
Financial instruments sold, not yet purchased | 3.6 |
Fair Value, Recurring | Agency mortgage-backed obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 1,989.2 | 2,599.8
Financial instruments sold, not yet purchased | 38.9 | 63.4
Fair Value, Recurring | Asset-backed obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 41.4 | 110.4
Fair Value, Recurring | Derivatives |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 172.3 | 144.3
Financial instruments sold, not yet purchased | 484.4 | 368.5
Fair Value, Recurring | Derivatives |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments sold, not yet purchased | 460.1 |
Fair Value, Recurring | Commodities leases |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 17.2 | 18.1
Financial instruments sold, not yet purchased |  | 0.9
Fair Value, Recurring | Other |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments sold, not yet purchased | 3.5 |
Fair Value, Recurring | Commodities warehouse receipts |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 26.9 | 21.4
Fair Value, Recurring | Exchange firm common stock |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 14.3 | 11.6
Fair Value, Recurring | Cash flow hedges |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments sold, not yet purchased | 24.3 |
Fair Value, Recurring | Mutual funds and other |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 20.3 | 10.5
Fair Value, Recurring | TBA and forward settling securities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Deposits with and receivables from broker-dealers, clearing organizations and counterparties, net | 93.4 | 19.0
Fair Value, Recurring | Foreign government obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Deposits with and receivables from broker-dealers, clearing organizations and counterparties, net | 15.5 | 12.2
Fair Value, Recurring | U.S. Treasury obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Deposits with and receivables from broker-dealers, clearing organizations and counterparties, net | 814.4 | 798.5
Fair Value, Recurring | Derivatives |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Deposits with and receivables from broker-dealers, clearing organizations and counterparties, net | (176.5) | 240.9
Fair Value, Recurring | Commodities warehouse receipts |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Securities and other assets segregated under federal and other regulations | 25.5 | 13.9
Fair Value, Recurring | U.S. Treasury obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Securities and other assets segregated under federal and other regulations | 165.2 | 0.2
Fair Value, Recurring | Certificates of deposit |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Assets | 6.7 | 7.9
Fair Value, Recurring | Money market mutual funds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Assets | 43.4 | 12.9
Fair Value, Recurring | Netting |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Cash and cash equivalents | 0.0 | 0.0
Securities and other assets segregated under federal and other regulations | 0.0 | 0.0
Deposits with and receivables from broker-dealers, clearing organizations and counterparties, net | (10,386.7) | (4,442.4)
Receivables from clients, net - Derivatives | (667.6) | (411.1)
Financial instruments owned | (908.2) | (500.4)
Total assets at fair value | (11,962.5) | (5,353.9)
Payables to clients - Derivatives | (10,517.8) | (4,278.4)
Financial instruments sold, not yet purchased | (800.5) | (335.0)
Total liabilities at fair value | (11,853.0) | (4,955.4)
Fair Value, Recurring | Netting | TBA and forward settling securities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Payable to broker-dealers, clearing organizations and counterparties | (58.0) | (39.5)
Fair Value, Recurring | Netting | Derivatives |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Payable to broker-dealers, clearing organizations and counterparties | (476.7) | (302.5)
Fair Value, Recurring | Netting | Payables to Broker-dealers, Clearing Organizations and Counterparties |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Payable to broker-dealers, clearing organizations and counterparties | (534.7) | (342.0)
Fair Value, Recurring | Netting | Contingent Consideration |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Accounts payable and other accrued liabilities - contingent liabilities | 0.0 | 0.0
Fair Value, Recurring | Netting | Physical commodities inventory |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Physical commodities inventory | 0.0 | 0.0
Fair Value, Recurring | Netting | Equity securities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Financial instruments sold, not yet purchased | 0.0 | 0.0
Fair Value, Recurring | Netting | Corporate and municipal bonds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Financial instruments sold, not yet purchased | 0.0 | 0.0
Fair Value, Recurring | Netting | U.S. Treasury obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Financial instruments sold, not yet purchased | 0.0 | 0.0
Fair Value, Recurring | Netting | U.S. government agency obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Financial instruments sold, not yet purchased | 0.0 |
Fair Value, Recurring | Netting | Agency mortgage-backed obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Financial instruments sold, not yet purchased | 0.0 | 0.0
Fair Value, Recurring | Netting | Asset-backed obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Fair Value, Recurring | Netting | Derivatives |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | (908.2) | (500.4)
Financial instruments sold, not yet purchased |  | (335.0)
Fair Value, Recurring | Netting | Derivatives |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments sold, not yet purchased | (800.5) |
Fair Value, Recurring | Netting | Commodities leases |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Financial instruments sold, not yet purchased |  | 0.0
Fair Value, Recurring | Netting | Other |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments sold, not yet purchased | 0.0 |
Fair Value, Recurring | Netting | Commodities warehouse receipts |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Fair Value, Recurring | Netting | Exchange firm common stock |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Fair Value, Recurring | Netting | Cash flow hedges |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments sold, not yet purchased | 0.0 |
Fair Value, Recurring | Netting | Mutual funds and other |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Fair Value, Recurring | Netting | TBA and forward settling securities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Deposits with and receivables from broker-dealers, clearing organizations and counterparties, net | (58.8) | (40.1)
Fair Value, Recurring | Netting | Foreign government obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Deposits with and receivables from broker-dealers, clearing organizations and counterparties, net | 0.0 | 0.0
Fair Value, Recurring | Netting | U.S. Treasury obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Deposits with and receivables from broker-dealers, clearing organizations and counterparties, net | 0.0 | 0.0
Fair Value, Recurring | Netting | Derivatives |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Deposits with and receivables from broker-dealers, clearing organizations and counterparties, net | (10,327.9) | (4,402.3)
Fair Value, Recurring | Netting | Commodities warehouse receipts |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Securities and other assets segregated under federal and other regulations | 0.0 | 0.0
Fair Value, Recurring | Netting | U.S. Treasury obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Securities and other assets segregated under federal and other regulations | 0.0 | 0.0
Fair Value, Recurring | Netting | Certificates of deposit |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Assets | 0.0 | 0.0
Fair Value, Recurring | Netting | Money market mutual funds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Assets | 0.0 | 0.0
Fair Value, Recurring | Level 1 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Cash and cash equivalents | 50.1 | 20.8
Securities and other assets segregated under federal and other regulations | 190.7 | 14.1
Deposits with and receivables from broker-dealers, clearing organizations and counterparties, net | 10,562.4 | 5,286.5
Receivables from clients, net - Derivatives | 62.2 | 0.0
Financial instruments owned | 1,252.2 | 989.6
Total assets at fair value | 12,217.7 | 6,422.2
Payables to clients - Derivatives | 9,702.3 | 4,413.8
Financial instruments sold, not yet purchased | 1,986.0 | 1,284.3
Total liabilities at fair value | 11,777.7 | 5,761.2
Fair Value, Recurring | Level 1 | TBA and forward settling securities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Payable to broker-dealers, clearing organizations and counterparties | 0.0 | 0.0
Fair Value, Recurring | Level 1 | Derivatives |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Payable to broker-dealers, clearing organizations and counterparties | 89.4 | 63.1
Fair Value, Recurring | Level 1 | Payables to Broker-dealers, Clearing Organizations and Counterparties |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Payable to broker-dealers, clearing organizations and counterparties | 89.4 | 63.1
Fair Value, Recurring | Level 1 | Contingent Consideration |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Accounts payable and other accrued liabilities - contingent liabilities | 0.0 | 0.0
Fair Value, Recurring | Level 1 | Physical commodities inventory |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Physical commodities inventory | 100.1 | 111.2
Fair Value, Recurring | Level 1 | Equity securities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 1,016.6 | 512.4
Financial instruments sold, not yet purchased | 963.6 | 429.9
Fair Value, Recurring | Level 1 | Corporate and municipal bonds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Financial instruments sold, not yet purchased | 0.0 | 0.0
Fair Value, Recurring | Level 1 | U.S. Treasury obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 176.2 | 433.1
Financial instruments sold, not yet purchased | 1,018.1 | 851.2
Fair Value, Recurring | Level 1 | U.S. government agency obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Financial instruments sold, not yet purchased | 0.0 |
Fair Value, Recurring | Level 1 | Agency mortgage-backed obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Financial instruments sold, not yet purchased | 0.0 | 0.0
Fair Value, Recurring | Level 1 | Asset-backed obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Fair Value, Recurring | Level 1 | Derivatives |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.8 | 0.6
Financial instruments sold, not yet purchased |  | 3.2
Fair Value, Recurring | Level 1 | Derivatives |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments sold, not yet purchased | 4.3 |
Fair Value, Recurring | Level 1 | Commodities leases |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Financial instruments sold, not yet purchased |  | 0.0
Fair Value, Recurring | Level 1 | Other |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments sold, not yet purchased | 0.0 |
Fair Value, Recurring | Level 1 | Commodities warehouse receipts |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 26.9 | 21.4
Fair Value, Recurring | Level 1 | Exchange firm common stock |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 14.3 | 11.6
Fair Value, Recurring | Level 1 | Cash flow hedges |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments sold, not yet purchased | 0.0 |
Fair Value, Recurring | Level 1 | Mutual funds and other |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 17.4 | 10.5
Fair Value, Recurring | Level 1 | TBA and forward settling securities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Deposits with and receivables from broker-dealers, clearing organizations and counterparties, net | 0.0 | 0.0
Fair Value, Recurring | Level 1 | Foreign government obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Deposits with and receivables from broker-dealers, clearing organizations and counterparties, net | 15.5 | 12.2
Fair Value, Recurring | Level 1 | U.S. Treasury obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Deposits with and receivables from broker-dealers, clearing organizations and counterparties, net | 814.4 | 798.5
Fair Value, Recurring | Level 1 | Derivatives |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Deposits with and receivables from broker-dealers, clearing organizations and counterparties, net | 9,732.5 | 4,475.8
Fair Value, Recurring | Level 1 | Commodities warehouse receipts |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Securities and other assets segregated under federal and other regulations | 25.5 | 13.9
Fair Value, Recurring | Level 1 | U.S. Treasury obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Securities and other assets segregated under federal and other regulations | 165.2 | 0.2
Fair Value, Recurring | Level 1 | Certificates of deposit |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Assets | 6.7 | 7.9
Fair Value, Recurring | Level 1 | Money market mutual funds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Assets | 43.4 | 12.9
Fair Value, Recurring | Level 2 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Cash and cash equivalents | 0.0 | 0.0
Securities and other assets segregated under federal and other regulations | 0.0 | 0.0
Deposits with and receivables from broker-dealers, clearing organizations and counterparties, net | 571.1 | 226.5
Receivables from clients, net - Derivatives | 589.9 | 413.7
Financial instruments owned | 3,812.2 | 3,865.4
Total assets at fair value | 5,235.5 | 4,754.3
Payables to clients - Derivatives | 269.4 | 156.1
Financial instruments sold, not yet purchased | 1,596.3 | 821.9
Total liabilities at fair value | 2,363.0 | 1,269.6
Fair Value, Recurring | Level 2 | TBA and forward settling securities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Payable to broker-dealers, clearing organizations and counterparties | 120.3 | 52.2
Fair Value, Recurring | Level 2 | Derivatives |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Payable to broker-dealers, clearing organizations and counterparties | 377.0 | 239.4
Fair Value, Recurring | Level 2 | Payables to Broker-dealers, Clearing Organizations and Counterparties |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Payable to broker-dealers, clearing organizations and counterparties | 497.3 | 291.6
Fair Value, Recurring | Level 2 | Contingent Consideration |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Accounts payable and other accrued liabilities - contingent liabilities | 0.0 | 0.0
Fair Value, Recurring | Level 2 | Physical commodities inventory |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Physical commodities inventory | 262.3 | 248.7
Fair Value, Recurring | Level 2 | Equity securities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 219.4 | 14.6
Financial instruments sold, not yet purchased | 191.5 | 6.2
Fair Value, Recurring | Level 2 | Corporate and municipal bonds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 120.3 | 150.8
Financial instruments sold, not yet purchased | 78.2 | 51.1
Fair Value, Recurring | Level 2 | U.S. Treasury obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Financial instruments sold, not yet purchased | 0.0 | 0.0
Fair Value, Recurring | Level 2 | U.S. government agency obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 342.1 | 327.6
Financial instruments sold, not yet purchased | 3.6 |
Fair Value, Recurring | Level 2 | Agency mortgage-backed obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 1,989.2 | 2,599.8
Financial instruments sold, not yet purchased | 38.9 | 63.4
Fair Value, Recurring | Level 2 | Asset-backed obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 41.4 | 110.4
Fair Value, Recurring | Level 2 | Derivatives |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 1,079.7 | 644.1
Financial instruments sold, not yet purchased |  | 700.3
Fair Value, Recurring | Level 2 | Derivatives |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments sold, not yet purchased | 1,256.3 |
Fair Value, Recurring | Level 2 | Commodities leases |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 17.2 | 18.1
Financial instruments sold, not yet purchased |  | 0.9
Fair Value, Recurring | Level 2 | Other |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments sold, not yet purchased | 3.5 |
Fair Value, Recurring | Level 2 | Commodities warehouse receipts |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Fair Value, Recurring | Level 2 | Exchange firm common stock |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Fair Value, Recurring | Level 2 | Cash flow hedges |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments sold, not yet purchased | 24.3 |
Fair Value, Recurring | Level 2 | Mutual funds and other |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 2.9 | 0.0
Fair Value, Recurring | Level 2 | TBA and forward settling securities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Deposits with and receivables from broker-dealers, clearing organizations and counterparties, net | 152.2 | 59.1
Fair Value, Recurring | Level 2 | Foreign government obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Deposits with and receivables from broker-dealers, clearing organizations and counterparties, net | 0.0 | 0.0
Fair Value, Recurring | Level 2 | U.S. Treasury obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Deposits with and receivables from broker-dealers, clearing organizations and counterparties, net | 0.0 | 0.0
Fair Value, Recurring | Level 2 | Derivatives |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Deposits with and receivables from broker-dealers, clearing organizations and counterparties, net | 418.9 | 167.4
Fair Value, Recurring | Level 2 | Commodities warehouse receipts |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Securities and other assets segregated under federal and other regulations | 0.0 | 0.0
Fair Value, Recurring | Level 2 | U.S. Treasury obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Securities and other assets segregated under federal and other regulations | 0.0 | 0.0
Fair Value, Recurring | Level 2 | Certificates of deposit |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Assets | 0.0 | 0.0
Fair Value, Recurring | Level 2 | Money market mutual funds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Assets | 0.0 | 0.0
Fair Value, Recurring | Level 3 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Cash and cash equivalents | 0.0 | 0.0
Securities and other assets segregated under federal and other regulations | 0.0 | 0.0
Deposits with and receivables from broker-dealers, clearing organizations and counterparties, net | 0.0 | 0.0
Receivables from clients, net - Derivatives |  |
Financial instruments owned | 0.0 | 0.0
Total assets at fair value | 0.0 | 0.0
Payables to clients - Derivatives | 0.0 |
Financial instruments sold, not yet purchased | 0.0 | 0.0
Total liabilities at fair value | 1.5 | 2.8
Fair Value, Recurring | Level 3 | TBA and forward settling securities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Payable to broker-dealers, clearing organizations and counterparties | 0.0 | 0.0
Fair Value, Recurring | Level 3 | Derivatives |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Payable to broker-dealers, clearing organizations and counterparties | 0.0 | 0.0
Fair Value, Recurring | Level 3 | Payables to Broker-dealers, Clearing Organizations and Counterparties |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Payable to broker-dealers, clearing organizations and counterparties | 0.0 | 0.0
Fair Value, Recurring | Level 3 | Contingent Consideration |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Accounts payable and other accrued liabilities - contingent liabilities | 1.5 | 2.8
Fair Value, Recurring | Level 3 | Physical commodities inventory |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Physical commodities inventory | 0.0 | 0.0
Fair Value, Recurring | Level 3 | Equity securities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Financial instruments sold, not yet purchased | 0.0 | 0.0
Fair Value, Recurring | Level 3 | Corporate and municipal bonds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Financial instruments sold, not yet purchased | 0.0 | 0.0
Fair Value, Recurring | Level 3 | U.S. Treasury obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Financial instruments sold, not yet purchased | 0.0 | 0.0
Fair Value, Recurring | Level 3 | U.S. government agency obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Financial instruments sold, not yet purchased | 0.0 |
Fair Value, Recurring | Level 3 | Agency mortgage-backed obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Financial instruments sold, not yet purchased | 0.0 | 0.0
Fair Value, Recurring | Level 3 | Asset-backed obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Fair Value, Recurring | Level 3 | Derivatives |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Financial instruments sold, not yet purchased |  | 0.0
Fair Value, Recurring | Level 3 | Derivatives |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments sold, not yet purchased | 0.0 |
Fair Value, Recurring | Level 3 | Commodities leases |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Financial instruments sold, not yet purchased |  | 0.0
Fair Value, Recurring | Level 3 | Other |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments sold, not yet purchased | 0.0 |
Fair Value, Recurring | Level 3 | Commodities warehouse receipts |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Fair Value, Recurring | Level 3 | Exchange firm common stock |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Fair Value, Recurring | Level 3 | Cash flow hedges |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments sold, not yet purchased | 0.0 |
Fair Value, Recurring | Level 3 | Mutual funds and other |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments owned | 0.0 | 0.0
Fair Value, Recurring | Level 3 | TBA and forward settling securities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Deposits with and receivables from broker-dealers, clearing organizations and counterparties, net | 0.0 | 0.0
Fair Value, Recurring | Level 3 | Foreign government obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Deposits with and receivables from broker-dealers, clearing organizations and counterparties, net | 0.0 | 0.0
Fair Value, Recurring | Level 3 | U.S. Treasury obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Deposits with and receivables from broker-dealers, clearing organizations and counterparties, net | 0.0 | 0.0
Fair Value, Recurring | Level 3 | Derivatives |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Deposits with and receivables from broker-dealers, clearing organizations and counterparties, net | 0.0 | 0.0
Fair Value, Recurring | Level 3 | Commodities warehouse receipts |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Securities and other assets segregated under federal and other regulations | 0.0 | 0.0
Fair Value, Recurring | Level 3 | U.S. Treasury obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Securities and other assets segregated under federal and other regulations | 0.0 | 0.0
Fair Value, Recurring | Level 3 | Certificates of deposit |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Assets | 0.0 | 0.0
Fair Value, Recurring | Level 3 | Money market mutual funds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Assets | $ 0.0 | $ 0.0

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