REVENUE RECOGNITION - Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 33,211	$ 33,250	$ 33,784	$ 36,633	$ 37,715	$ 37,176	$ 37,359	$ 37,120	$ 136,878	$ 149,370	$ 161,570
Dice [Member]
Disaggregation of Revenue [Line Items]
Revenues									82,190	92,527	94,438
ClearanceJobs [Member]
Disaggregation of Revenue [Line Items]
Revenues									28,977	24,745	21,086
Dice Europe [Member]
Disaggregation of Revenue [Line Items]
Revenues									0	0	2,976
eFinancial Careers [Member]
Disaggregation of Revenue [Line Items]
Revenues									25,711	32,098	33,758
Hcareers [Member]
Disaggregation of Revenue [Line Items]
Revenues									0	0	5,329
Rigzone [Member]
Disaggregation of Revenue [Line Items]
Revenues									0	0	3,771
Biospace [Member]
Disaggregation of Revenue [Line Items]
Revenues									0	0	212
Tech-Focused [Member]
Disaggregation of Revenue [Line Items]
Revenues									136,878	149,370	152,258
Tech-Focused [Member] | Dice [Member]
Disaggregation of Revenue [Line Items]
Revenues									82,190	92,527	94,438
Tech-Focused [Member] | ClearanceJobs [Member]
Disaggregation of Revenue [Line Items]
Revenues									28,977	24,745	21,086
Tech-Focused [Member] | Dice Europe [Member]
Disaggregation of Revenue [Line Items]
Revenues									0	0	2,976
Tech-Focused [Member] | eFinancial Careers [Member]
Disaggregation of Revenue [Line Items]
Revenues									25,711	32,098	33,758
Tech-Focused [Member] | Hcareers [Member]
Disaggregation of Revenue [Line Items]
Revenues									0	0	0
Tech-Focused [Member] | Rigzone [Member]
Disaggregation of Revenue [Line Items]
Revenues									0	0	0
Tech-Focused [Member] | Biospace [Member]
Disaggregation of Revenue [Line Items]
Revenues									0	0	0
Other [Member]
Disaggregation of Revenue [Line Items]
Revenues									0	0	9,312
Other [Member] | Dice [Member]
Disaggregation of Revenue [Line Items]
Revenues									0	0	0
Other [Member] | ClearanceJobs [Member]
Disaggregation of Revenue [Line Items]
Revenues									0	0	0
Other [Member] | Dice Europe [Member]
Disaggregation of Revenue [Line Items]
Revenues									0	0	0
Other [Member] | eFinancial Careers [Member]
Disaggregation of Revenue [Line Items]
Revenues									0	0	0
Other [Member] | Hcareers [Member]
Disaggregation of Revenue [Line Items]
Revenues											5,329
Other [Member] | Rigzone [Member]
Disaggregation of Revenue [Line Items]
Revenues									0	0	3,771
Other [Member] | Biospace [Member]
Disaggregation of Revenue [Line Items]
Revenues										0	212
Corporate and Other [Member]
Disaggregation of Revenue [Line Items]
Revenues									$ 0	$ 0	$ 9,312