For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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Amount, before 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.

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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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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Revenue - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
Revenue - Narrative (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Contract asset	$ 0		$ 0		$ 55
Contract revenue
Disaggregation of Revenue [Line Items]
Revenue recognized from previously recorded contract liabilities	$ 206	$ 1,056	$ 819	$ 1,865
Customer Concentration Risk \| Accounts receivable \| Largest customer
Disaggregation of Revenue [Line Items]
Concentration risk			34.00%		35.00%
Customer Concentration Risk \| Accounts receivable \| Second largest customer
Disaggregation of Revenue [Line Items]
Concentration risk			18.00%		12.00%