Product Warranty (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Product Warranties Disclosures [Abstract]
Warranty costs		$ 3,477	$ 3,501	$ 8,342
Estimate additional accrual amount	$ 34,100

Warranty expense is the cost associated with a vendor or manufacturer's commitment to repair or replace a product, should it not perform as intended during a specified period of time. In other words, it's the cost of repairing or replacing defective products after they have been sold to customers.

No definition available.

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