Accounts Receivable - Accounts Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Receivables [Abstract]
Accounts receivable	$ 59,242	$ 74,689
Allowance for doubtful accounts	(944)	(1,073)
Accounts receivable - net	$ 58,298	$ 73,616