Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowance for uncollectible receivables
Balance at beginning of period	$ 3,764	$ 11,453	$ 4,217
Charge to expenses	2,859	(2,275)	7,375
Additions/(deductions)	(4,344)	(5,414)	(139)
Balance at end of period	2,279	3,764	11,453
Valuation allowance for deferred tax assets
Balance at beginning of period	8,361	713	393
Charge to expenses	16,386	7,648	320
Balance at end of period	$ 24,747	$ 8,361	$ 713