Amount of cash and cash equivalents restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Name:	us-gaap_RestrictedCashAndCashEquivalents
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Summary of Significant Accounting Policies - Reconciliation Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 61,031	$ 45,072
Restricted cash included in:
Total cash, cash equivalents and restricted cash	61,613	45,650	$ 61,749	$ 34,335
Prepaid expenses and other current assets
Restricted cash included in:
Restricted cash	57	0
Non-current inventory and other
Restricted cash included in:
Restricted cash	$ 525	$ 578