Accounting Policies - Summary of Changes in Allowance for Doubtful Accounts and Sales Allowances (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Allowance for Doubtful Accounts Receivable [Roll Forward]
Allowances, at beginning of period	$ 7,147	$ 6,591
Charged as a reduction of revenue	1,279	2,398
Charged to bad debt expense in general and administrative expenses	232	2,225
Write-offs, net of recoveries	(2,509)	(3,327)
Allowances, at end of period	$ 6,149	$ 7,887