Segment Reporting and Geographic Information (Tables)

3 Months Ended

Mar. 31, 2017

Segment Reporting [Abstract]

Revenues by Geographic Region

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

	Three months ended March 31,
	2016			2017
United States		97	%		96	%
Canada		3	%		4	%
Other countries	*			*
		100	%		100	%

* Less than 1% of revenue.