Revenue Recognition - Comparison to Amounts if ASC 605 Had Been in Effect (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenue Recognition
Net revenues	$ 50,460	$ 34,735	$ 88,037	$ 67,144
Operating expenses	43,282	25,771	75,793	54,114
Operating income	$ 7,178	$ 8,964	$ 12,244	$ 13,030