Significant Risk Concentrations (Tables)

6 Months Ended

Jun. 30, 2018

Risks And Uncertainties [Abstract]

Summary of Rebate Program Recorded Under Rebate Credits

Under this rebate program, we recorded rebate credits as follows (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2018		2017		2018		2017
Reductions to cost of revenue	$	158	$	87	$	418	$	197
Reductions to marketing expense	$	113	$	219	$	379	$	374