Schedule II - Valuation and Qualifying Accounts and Reserves (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Allowance for doubtful accounts
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	$ 35
Charged to Costs & Expenses	0	$ 35
Charged to Other Accounts	0	0
Accounts Written Off or Deductions	(35)	0
Balance at End of Period		35
Deferred tax valuation allowance
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	29,203	15,167
Charged to Costs & Expenses	0	0
Charged to Other Accounts	8,620	14,036
Accounts Written Off or Deductions	0	0
Balance at End of Period	$ 37,823	$ 29,203