Accounts Receivable - Additional Information (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounts Notes and Loans Receivable [Line Items]
Sales-type leases term of lease	36 months
Allowance for doubtful accounts	$ 15,141	$ 14,277	$ 10,889	$ 10,494	$ 4,408
Accounts Receivable | Customer Concentration Risk
Accounts Notes and Loans Receivable [Line Items]
Allowance for doubtful accounts	15,141			10,494
Trade Receivables and Long-term Receivables
Accounts Notes and Loans Receivable [Line Items]
Financing receivables, consisting of sales-type leases	$ 51,845			$ 72,602