Accounts Receivable - Activity in Accounts Receivable Reserves (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 1,534	$ 1,281	$ 925
Charges to income from operations	5,116	3,824	3,407
Collections from customers previously reserved and other	(4,770)	(3,571)	(3,051)
Ending balance	$ 1,880	$ 1,534	$ 1,281