Revenue Recognition - Disaggregated Revenue (Details) - Tech-Focused [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Disaggregated revenue	$ 33,250	$ 37,176	$ 103,667	$ 111,655
Dice [Member]
Disaggregation of Revenue [Line Items]
Disaggregated revenue	19,823	22,915	62,797	69,276
ClearanceJobs [Member]
Disaggregation of Revenue [Line Items]
Disaggregated revenue	7,326	6,320	21,333	18,116
eFinancial Careers [Member]
Disaggregation of Revenue [Line Items]
Disaggregated revenue	$ 6,101	$ 7,941	$ 19,537	$ 24,263