Revenue From Contracts With Customers - Summary of Information about Receivables and Contract Liabilities from Contracts with Customers (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Schedule Of Contract Balances [Line Items]
Accounts receivable, current	$ 2,012	$ 3,384
Notes receivable, current	444	502
Notes receivable, long-term	452	827
Contract liability, current	923	777
Notes and Other Receivables, Long-Term, Net
Schedule Of Contract Balances [Line Items]
Notes receivable, long-term	452	827
Deferred Revenue
Schedule Of Contract Balances [Line Items]
Contract liability, current	923	777
Other Long-Term Liabilities
Schedule Of Contract Balances [Line Items]
Contract liability, non-current	$ 128	$ 118