Segment Reporting and Geographic Information (Tables)

9 Months Ended

Sep. 30, 2018

Segment Reporting [Abstract]

Revenues by Geographic Region

Revenues by geographic region are as follows (in percentages):

	Nine Months Ended September 30,						Three Months Ended September 30,
	2017			2018			2017			2018
United States		96	%		99	%		96	%		99	%
Canada		4	%		1	%		4	%		1	%
Other countries	*			*			*			*
		100	%		100	%		100	%		100	%

* Less than 1% of revenue.