Revenue from Contracts with Customers - Contract Asset and Liability Balances (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Change in Contract Asset Balance
Beginning of period balance	$ 4,718	$ 3,849	$ 4,578	$ 2,881
Commission costs and upfront payments to a customer capitalized in period	607	333	2,429	2,438
Amortization of contract assets	(1,046)	(613)	(2,728)	(1,750)
End of period balance	4,279	3,569	4,279	3,569
Change In Contract With Customer, Liability [Roll Forward]
Beginning of period balance	11,537	10,980	10,498	11,176
Revenue deferred in period	3,425	542	9,118	3,013
Revenue recognized from amounts included in contract liabilities	(2,090)	(1,499)	(6,744)	(4,166)
End of period balance	$ 12,872	$ 10,023	$ 12,872	$ 10,023