Basis of Presentation - Disaggregation of Revenue by Product Line (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
Disaggregation of Revenue [Line Items]
Total revenues	$ 11,335
Screening revenues
Disaggregation of Revenue [Line Items]
Total revenues	7,345
Portal revenues
Disaggregation of Revenue [Line Items]
Total revenues	3,030
Coaching revenues
Disaggregation of Revenue [Line Items]
Total revenues	589
Other revenues
Disaggregation of Revenue [Line Items]
Total revenues	$ 371