Supplemental Consolidated Financial Statement Information - Allowance for Doubtful Accounts (Details)	12 Months Ended
	Dec. 31, 2020 USD ($)
Allowance for doubtful accounts
Beginning Balance	$ (250,000)
Additional provisions to allowance	(1,625,000)
Ending Balance	(250,000)
Accounts Receivable
Allowance for doubtful accounts
Write-offs against allowance	191,000
Notes Receivable
Allowance for doubtful accounts
Write-offs against allowance	$ 1,434,000