REVENUE RECOGNITION - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenue	$ 209,200	$ 200,717	$ 607,128	$ 615,577
Temporary Staffing Services [Member]
Disaggregation of Revenue [Line Items]
Revenue	200,876	192,468	583,253	589,478
Other Services [Member]
Disaggregation of Revenue [Line Items]
Revenue	8,324	8,249	23,875	26,099
Nurse And Allied Staffing [Member]
Disaggregation of Revenue [Line Items]
Revenue	184,974	175,945	541,398	539,488
Nurse And Allied Staffing [Member] | Temporary Staffing Services [Member]
Disaggregation of Revenue [Line Items]
Revenue	181,640	172,825	532,036	529,662
Nurse And Allied Staffing [Member] | Other Services [Member]
Disaggregation of Revenue [Line Items]
Revenue	3,334	3,120	9,362	9,826
Physician Staffing [Member]
Disaggregation of Revenue [Line Items]
Revenue	20,407	21,158	54,594	64,052
Physician Staffing [Member] | Temporary Staffing Services [Member]
Disaggregation of Revenue [Line Items]
Revenue	19,236	19,643	51,217	59,816
Physician Staffing [Member] | Other Services [Member]
Disaggregation of Revenue [Line Items]
Revenue	1,171	1,515	3,377	4,236
Search [Member]
Disaggregation of Revenue [Line Items]
Revenue	3,819	3,614	11,136	12,037
Search [Member] | Temporary Staffing Services [Member]
Disaggregation of Revenue [Line Items]
Revenue	0	0	0	0
Search [Member] | Other Services [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ 3,819	$ 3,614	$ 11,136	$ 12,037