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