REVENUE RECOGNITION (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Abstract]
Total revenues	$ 70,113	$ 70,078	$ 61,120	$ 61,889	$ 67,401	$ 67,308	$ 61,865	$ 65,279	$ 263,200	$ 261,853	$ 285,559
Unearned tuition	22,545				24,647				22,545	24,647
Revenue recognized included in contract liability									24,500
ASU 2016-10 [Member]
Disaggregation of Revenue [Abstract]
Unearned tuition	$ 22,500				$ 24,600				22,500	24,600
Services Transferred at a Point in Time [Member]
Disaggregation of Revenue [Abstract]
Total revenues									14,257	11,875	12,177
Services Transferred over Time [Member]
Disaggregation of Revenue [Abstract]
Total revenues									248,943	249,978	273,382
Transportation and Skilled Trades Segment [Member]
Disaggregation of Revenue [Abstract]
Total revenues									185,263	181,328	182,277
Transportation and Skilled Trades Segment [Member] | Services Transferred at a Point in Time [Member]
Disaggregation of Revenue [Abstract]
Total revenues									10,351	8,987	8,856
Transportation and Skilled Trades Segment [Member] | Services Transferred over Time [Member]
Disaggregation of Revenue [Abstract]
Total revenues									174,912	172,341	173,421
Healthcare and Other Professions Segment [Member]
Disaggregation of Revenue [Abstract]
Total revenues									72,135	63,641	62,870
Healthcare and Other Professions Segment [Member] | Services Transferred at a Point in Time [Member]
Disaggregation of Revenue [Abstract]
Total revenues									3,834	2,860	2,765
Healthcare and Other Professions Segment [Member] | Services Transferred over Time [Member]
Disaggregation of Revenue [Abstract]
Total revenues									68,301	60,781	60,105
Transitional Segment [Member]
Disaggregation of Revenue [Abstract]
Total revenues									5,802	16,884	40,412
Transitional Segment [Member] | Services Transferred at a Point in Time [Member]
Disaggregation of Revenue [Abstract]
Total revenues									72	28	556
Transitional Segment [Member] | Services Transferred over Time [Member]
Disaggregation of Revenue [Abstract]
Total revenues									$ 5,730	$ 16,856	$ 39,856