Uniform Net Capital Rule Requirements - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($) subsidiary	Dec. 31, 2019 USD ($)
Uniform Net Capital Rule Requirements
Number of subsidiaries registered as broker dealers | subsidiary	2
Maximum ratio of aggregate indebtedness to net capital	15.0
Minimum net capital | $	$ 250	$ 250
Net capital percentage of debit balances	2.00%	2.00%