Revenue Recognition - Change In Balance Of Total Deferred Revenue (Details) - USD ($) $ in Thousands		3 Months Ended	9 Months Ended	12 Months Ended
Dec. 31, 2020	Sep. 30, 2021	Sep. 30, 2021	Dec. 31, 2020
Unearned Revenue
Beginning balance			$ 2,759	$ 566
Additions			3,161	4,117
Revenue Recognized				(1,924)
Revenue Recognized	$ (600)	$ (200)	(1,088)
Ending balance	$ 2,759	$ 4,832	$ 4,832	$ 2,759

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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=123360276&loc=SL49130531-203044

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130549-203045

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=123360276&loc=SL49130532-203044

Name:	us-gaap_ContractWithCustomerLiability
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant