Basis of Presentation and Significant Accounting Policies - Use of Estimates (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Basis of Presentation and Significant Accounting Policies
Contingent liabilities	$ 1,410	$ 798

Amount of liability for consideration received or receivable from customer which is not included in transaction price, when consideration is expected to be refunded to customer, classified as current.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 55
-Paragraph 27
-URI http://asc.fasb.org/extlink&oid=121551570&loc=SL49130611-203046-203046

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