Fair Value (Details) - USD ($) $ in Thousands | Mar. 31, 2022 | Dec. 31, 2021 |
Investments in securities [Abstract] | | |
Investments in securities | $ 37,982 | $ 32,344 |
Common Stocks [Member] | | |
Investments in securities [Abstract] | | |
Investments in securities | 15,261 | 16,210 |
Actively Managed Semi-transparent EFTs [Member] | | |
Investments in securities [Abstract] | | |
Investments in securities | 16,539 | 9,599 |
Open-end Funds [Member] | | |
Investments in securities [Abstract] | | |
Investments in securities | 5,664 | 5,995 |
Closed-end Funds [Member] | | |
Investments in securities [Abstract] | | |
Investments in securities | 514 | 534 |
Other [Member] | | |
Investments in securities [Abstract] | | |
Investments in securities | 4 | 6 |
Recurring Basis [Member] | | |
Assets [Abstract] | | |
Cash equivalents | 143,983 | 141,394 |
Investments in securities [Abstract] | | |
Investments in securities | 37,982 | 32,344 |
Total assets at fair value | 181,965 | 173,738 |
Recurring Basis [Member] | Common Stocks [Member] | | |
Investments in securities [Abstract] | | |
Investments in securities | 15,261 | 16,210 |
Recurring Basis [Member] | Actively Managed Semi-transparent EFTs [Member] | | |
Investments in securities [Abstract] | | |
Investments in securities | 16,539 | 9,599 |
Recurring Basis [Member] | Open-end Funds [Member] | | |
Investments in securities [Abstract] | | |
Investments in securities | 5,664 | 5,995 |
Recurring Basis [Member] | Closed-end Funds [Member] | | |
Investments in securities [Abstract] | | |
Investments in securities | 514 | 534 |
Recurring Basis [Member] | Other [Member] | | |
Investments in securities [Abstract] | | |
Investments in securities | 4 | 6 |
Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | | |
Assets [Abstract] | | |
Cash equivalents | 143,983 | 141,394 |
Investments in securities [Abstract] | | |
Investments in securities | 37,982 | 32,344 |
Total assets at fair value | 181,965 | 173,738 |
Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Common Stocks [Member] | | |
Investments in securities [Abstract] | | |
Investments in securities | 15,261 | 16,210 |
Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Actively Managed Semi-transparent EFTs [Member] | | |
Investments in securities [Abstract] | | |
Investments in securities | 16,539 | 9,599 |
Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Open-end Funds [Member] | | |
Investments in securities [Abstract] | | |
Investments in securities | 5,664 | 5,995 |
Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Closed-end Funds [Member] | | |
Investments in securities [Abstract] | | |
Investments in securities | 514 | 534 |
Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Other [Member] | | |
Investments in securities [Abstract] | | |
Investments in securities | 4 | 6 |
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | | |
Assets [Abstract] | | |
Cash equivalents | 0 | 0 |
Investments in securities [Abstract] | | |
Investments in securities | 0 | 0 |
Total assets at fair value | 0 | 0 |
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Common Stocks [Member] | | |
Investments in securities [Abstract] | | |
Investments in securities | 0 | 0 |
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Actively Managed Semi-transparent EFTs [Member] | | |
Investments in securities [Abstract] | | |
Investments in securities | 0 | 0 |
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Open-end Funds [Member] | | |
Investments in securities [Abstract] | | |
Investments in securities | 0 | 0 |
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Closed-end Funds [Member] | | |
Investments in securities [Abstract] | | |
Investments in securities | 0 | 0 |
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Other [Member] | | |
Investments in securities [Abstract] | | |
Investments in securities | 0 | 0 |
Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member] | | |
Assets [Abstract] | | |
Cash equivalents | 0 | 0 |
Investments in securities [Abstract] | | |
Investments in securities | 0 | 0 |
Total assets at fair value | 0 | 0 |
Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member] | Common Stocks [Member] | | |
Investments in securities [Abstract] | | |
Investments in securities | 0 | 0 |
Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member] | Actively Managed Semi-transparent EFTs [Member] | | |
Investments in securities [Abstract] | | |
Investments in securities | 0 | 0 |
Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member] | Open-end Funds [Member] | | |
Investments in securities [Abstract] | | |
Investments in securities | 0 | 0 |
Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member] | Closed-end Funds [Member] | | |
Investments in securities [Abstract] | | |
Investments in securities | 0 | 0 |
Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other [Member] | | |
Investments in securities [Abstract] | | |
Investments in securities | $ 0 | $ 0 |