Revenue Recognition Contract Balances with Customers (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2021	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Receivables from Customers	$ 56,577	$ 55,600
Contract with Customer, Asset, Net, Current	18	18
Contract with Customer, Asset, Net, Noncurrent	5,034	4,816
Customer deposits and refunds	433	$ 644
Increase (Decrease) in Receivables	977
Increase (Decrease) in Other Current Assets	0
Increase (Decrease) in Other Noncurrent Assets	218
Increase (Decrease) in Other Current Liabilities	(211)
Contract with Customer, Liability, Revenue Recognized	$ 400

Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time, classified as current.

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Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as current.

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Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

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Amount of increase (decrease) in current assets classified as other.

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The increase (decrease) during the reporting period in the total amount due within one year (or one operating cycle) from all parties, associated with underlying transactions that are classified as operating activities.

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Amount due from customers for fees and charges arising from transactions related to the entity's brokerage activities and operations.

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