Significant Risk Concentrations (Tables)

3 Months Ended

Mar. 31, 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 March 31,
	2018		2017
Reductions to cost of revenue	$	260	$	110
Reductions to marketing expense	$	266	$	155